From 354681b298b4369d2fc614e4c6351ce8fd4a6def Mon Sep 17 00:00:00 2001
From: sneak <sneak@sneak.berlin>
Date: Wed, 28 May 2025 14:06:29 -0700
Subject: [PATCH] latest

---
 LICENSE                                    |  13 +
 Makefile                                   |   2 +-
 README.md                                  |  16 +-
 go.mod                                     |   2 +
 go.sum                                     |   5 +
 internal/agehd/agehd_test.go               | 223 -----
 {internal => pkg}/agehd/README.md          |   8 +-
 {internal => pkg}/agehd/agehd.go           |   2 +-
 pkg/agehd/agehd_test.go                    | 928 +++++++++++++++++++++
 {internal => pkg}/bip85/README.md          |   4 +-
 {internal => pkg}/bip85/bip-0085.mediawiki |   0
 {internal => pkg}/bip85/bip85.go           |   0
 {internal => pkg}/bip85/bip85_test.go      |   0
 test_secret_manager.sh                     | 785 +++++++++++++++++
 14 files changed, 1749 insertions(+), 239 deletions(-)
 create mode 100644 LICENSE
 delete mode 100644 internal/agehd/agehd_test.go
 rename {internal => pkg}/agehd/README.md (96%)
 rename {internal => pkg}/agehd/agehd.go (98%)
 create mode 100644 pkg/agehd/agehd_test.go
 rename {internal => pkg}/bip85/README.md (97%)
 rename {internal => pkg}/bip85/bip-0085.mediawiki (100%)
 rename {internal => pkg}/bip85/bip85.go (100%)
 rename {internal => pkg}/bip85/bip85_test.go (100%)
 create mode 100755 test_secret_manager.sh

diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..a8dd1dd
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,13 @@
+            DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
+                    Version 2, December 2004
+
+ Copyright (C) 2004 Sam Hocevar <sam@hocevar.net>
+
+ Everyone is permitted to copy and distribute verbatim or modified
+ copies of this license document, and changing it is allowed as long
+ as the name is changed.
+
+            DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
+   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
+
+  0. You just DO WHAT THE FUCK YOU WANT TO. 
\ No newline at end of file
diff --git a/Makefile b/Makefile
index f70e3d3..040dad5 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 default: test
 
-test:
+test: lint
 	go test -v ./...
 
 lint:
diff --git a/README.md b/README.md
index 3ee5fd9..2125cba 100644
--- a/README.md
+++ b/README.md
@@ -12,15 +12,15 @@
 
   the first and initial vault is titled `default`.
 
-* `secret init` initializes a new vault.  this will create a new profile and
-  generate a new long-term keypair.  the long-term keypair is used to
-  encrypt and decrypt secrets.  the long-term keypair is stored in the
-  vault.  the private key for the vault is encrypted to a short-term
-  keypair.  the short-term keypair private key is encrypted to a passphrase.
-  to generate the long-term keypair, a random bip32 seed phrase is
-  generated, then the process proceeds exactly as `secret import private`.
+* `secret init` initializes a new vault and imports a user-provided BIP39 
+  mnemonic phrase. The user must provide their own mnemonic phrase. The 
+  long-term keypair is derived from this mnemonic. The long-term keypair is
+  used to encrypt and decrypt secrets. The long-term keypair is stored in the 
+  vault. The private key for the vault is encrypted to a short-term keypair. 
+  The short-term keypair private key is encrypted to a passphrase.
 
-  the randomly generated bip32 seed phrase is shown to the user.
+  Use `secret generate mnemonic` to create a new BIP39 mnemonic phrase if you 
+  need one.
 
   if there is already a vault, `secret init` exits with an error.
 
diff --git a/go.mod b/go.mod
index 709c8a1..3b4aa3b 100644
--- a/go.mod
+++ b/go.mod
@@ -18,7 +18,9 @@ require (
 	github.com/btcsuite/btcd/chaincfg/chainhash v1.1.0 // indirect
 	github.com/decred/dcrd/dcrec/secp256k1/v4 v4.0.1 // indirect
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect
+	github.com/mattn/go-isatty v0.0.20 // indirect
 	github.com/spf13/pflag v1.0.6 // indirect
 	golang.org/x/sys v0.33.0 // indirect
+	golang.org/x/term v0.32.0 // indirect
 	golang.org/x/text v0.25.0 // indirect
 )
diff --git a/go.sum b/go.sum
index cf0a31b..1008d45 100644
--- a/go.sum
+++ b/go.sum
@@ -60,6 +60,8 @@ github.com/jessevdk/go-flags v0.0.0-20141203071132-1679536dcc89/go.mod h1:4FA24M
 github.com/jessevdk/go-flags v1.4.0/go.mod h1:4FA24M0QyGHXBuZZK/XkWh8h0e1EYbRYJSGM75WSRxI=
 github.com/jrick/logrotate v1.0.0/go.mod h1:LNinyqDIJnpAur+b8yyulnQw/wDuN1+BYKlTRt3OuAQ=
 github.com/kkdai/bstream v0.0.0-20161212061736-f391b8402d23/go.mod h1:J+Gs4SYgM6CZQHDETBtE9HaSEkGmuNXF86RwHhHUvq4=
+github.com/mattn/go-isatty v0.0.20 h1:xfD0iDuEKnDkl03q4limB+vH+GxLEtL/jb4xVJSWWEY=
+github.com/mattn/go-isatty v0.0.20/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
 github.com/nxadm/tail v1.4.4/go.mod h1:kenIhsEOeOJmVchQTgglprH7qJGnHDVpk1VPCcaMI8A=
 github.com/onsi/ginkgo v1.6.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
 github.com/onsi/ginkgo v1.7.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
@@ -109,8 +111,11 @@ golang.org/x/sys v0.0.0-20191120155948-bd437916bb0e/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20200323222414-85ca7c5b95cd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200519105757-fe76b779f299/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200814200057-3d37ad5750ed/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.33.0 h1:q3i8TbbEz+JRD9ywIRlyRAQbM0qF7hu24q3teo2hbuw=
 golang.org/x/sys v0.33.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k=
+golang.org/x/term v0.32.0 h1:DR4lr0TjUs3epypdhTOkMmuF5CDFJ/8pOnbzMZPQ7bg=
+golang.org/x/term v0.32.0/go.mod h1:uZG1FhGx848Sqfsq4/DlJr3xGGsYMu/L5GW4abiaEPQ=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
diff --git a/internal/agehd/agehd_test.go b/internal/agehd/agehd_test.go
deleted file mode 100644
index cb6cdcb..0000000
--- a/internal/agehd/agehd_test.go
+++ /dev/null
@@ -1,223 +0,0 @@
-package agehd
-
-import (
-	"bytes"
-	"io"
-	"testing"
-
-	"filippo.io/age"
-)
-
-const (
-	mnemonic = "abandon abandon abandon abandon abandon " +
-		"abandon abandon abandon abandon abandon abandon about"
-
-	// Test xprv from BIP85 test vectors
-	testXPRV = "xprv9s21ZrQH143K2LBWUUQRFXhucrQqBpKdRRxNVq2zBqsx8HVqFk2uYo8kmbaLLHRdqtQpUm98uKfu3vca1LqdGhUtyoFnCNkfmXRyPXLjbKb"
-)
-
-func TestEncryptDecrypt(t *testing.T) {
-	id, err := DeriveIdentity(mnemonic, 0)
-	if err != nil {
-		t.Fatalf("derive: %v", err)
-	}
-
-	t.Logf("secret:    %s", id.String())
-	t.Logf("recipient: %s", id.Recipient().String())
-
-	var ct bytes.Buffer
-	w, err := age.Encrypt(&ct, id.Recipient())
-	if err != nil {
-		t.Fatalf("encrypt init: %v", err)
-	}
-	if _, err = io.WriteString(w, "hello world"); err != nil {
-		t.Fatalf("write: %v", err)
-	}
-	if err = w.Close(); err != nil {
-		t.Fatalf("encrypt close: %v", err)
-	}
-
-	r, err := age.Decrypt(bytes.NewReader(ct.Bytes()), id)
-	if err != nil {
-		t.Fatalf("decrypt init: %v", err)
-	}
-	dec, err := io.ReadAll(r)
-	if err != nil {
-		t.Fatalf("read: %v", err)
-	}
-
-	if got := string(dec); got != "hello world" {
-		t.Fatalf("round-trip mismatch: %q", got)
-	}
-}
-
-func TestDeriveIdentityFromXPRV(t *testing.T) {
-	id, err := DeriveIdentityFromXPRV(testXPRV, 0)
-	if err != nil {
-		t.Fatalf("derive from xprv: %v", err)
-	}
-
-	t.Logf("xprv secret:    %s", id.String())
-	t.Logf("xprv recipient: %s", id.Recipient().String())
-
-	// Test encryption/decryption with xprv-derived identity
-	var ct bytes.Buffer
-	w, err := age.Encrypt(&ct, id.Recipient())
-	if err != nil {
-		t.Fatalf("encrypt init: %v", err)
-	}
-	if _, err = io.WriteString(w, "hello from xprv"); err != nil {
-		t.Fatalf("write: %v", err)
-	}
-	if err = w.Close(); err != nil {
-		t.Fatalf("encrypt close: %v", err)
-	}
-
-	r, err := age.Decrypt(bytes.NewReader(ct.Bytes()), id)
-	if err != nil {
-		t.Fatalf("decrypt init: %v", err)
-	}
-	dec, err := io.ReadAll(r)
-	if err != nil {
-		t.Fatalf("read: %v", err)
-	}
-
-	if got := string(dec); got != "hello from xprv" {
-		t.Fatalf("round-trip mismatch: %q", got)
-	}
-}
-
-func TestDeterministicDerivation(t *testing.T) {
-	// Test that the same mnemonic and index always produce the same identity
-	id1, err := DeriveIdentity(mnemonic, 0)
-	if err != nil {
-		t.Fatalf("derive 1: %v", err)
-	}
-
-	id2, err := DeriveIdentity(mnemonic, 0)
-	if err != nil {
-		t.Fatalf("derive 2: %v", err)
-	}
-
-	if id1.String() != id2.String() {
-		t.Fatalf("identities should be deterministic: %s != %s", id1.String(), id2.String())
-	}
-
-	// Test that different indices produce different identities
-	id3, err := DeriveIdentity(mnemonic, 1)
-	if err != nil {
-		t.Fatalf("derive 3: %v", err)
-	}
-
-	if id1.String() == id3.String() {
-		t.Fatalf("different indices should produce different identities")
-	}
-
-	t.Logf("Index 0: %s", id1.String())
-	t.Logf("Index 1: %s", id3.String())
-}
-
-func TestDeterministicXPRVDerivation(t *testing.T) {
-	// Test that the same xprv and index always produce the same identity
-	id1, err := DeriveIdentityFromXPRV(testXPRV, 0)
-	if err != nil {
-		t.Fatalf("derive 1: %v", err)
-	}
-
-	id2, err := DeriveIdentityFromXPRV(testXPRV, 0)
-	if err != nil {
-		t.Fatalf("derive 2: %v", err)
-	}
-
-	if id1.String() != id2.String() {
-		t.Fatalf("xprv identities should be deterministic: %s != %s", id1.String(), id2.String())
-	}
-
-	// Test that different indices with same xprv produce different identities
-	id3, err := DeriveIdentityFromXPRV(testXPRV, 1)
-	if err != nil {
-		t.Fatalf("derive 3: %v", err)
-	}
-
-	if id1.String() == id3.String() {
-		t.Fatalf("different indices should produce different identities")
-	}
-
-	t.Logf("XPRV Index 0: %s", id1.String())
-	t.Logf("XPRV Index 1: %s", id3.String())
-}
-
-func TestMnemonicVsXPRVConsistency(t *testing.T) {
-	// Test that deriving from mnemonic and from the corresponding xprv produces the same result
-	// Note: This test is removed because the test mnemonic and test xprv are from different sources
-	// and are not expected to produce the same results.
-	t.Skip("Skipping consistency test - test mnemonic and xprv are from different sources")
-}
-
-func TestEntropyLength(t *testing.T) {
-	// Test that DeriveEntropy returns exactly 32 bytes
-	entropy, err := DeriveEntropy(mnemonic, 0)
-	if err != nil {
-		t.Fatalf("derive entropy: %v", err)
-	}
-
-	if len(entropy) != 32 {
-		t.Fatalf("expected 32 bytes of entropy, got %d", len(entropy))
-	}
-
-	t.Logf("Entropy (32 bytes): %x", entropy)
-
-	// Test that DeriveEntropyFromXPRV returns exactly 32 bytes
-	entropyXPRV, err := DeriveEntropyFromXPRV(testXPRV, 0)
-	if err != nil {
-		t.Fatalf("derive entropy from xprv: %v", err)
-	}
-
-	if len(entropyXPRV) != 32 {
-		t.Fatalf("expected 32 bytes of entropy from xprv, got %d", len(entropyXPRV))
-	}
-
-	t.Logf("XPRV Entropy (32 bytes): %x", entropyXPRV)
-
-	// Note: We don't compare the entropy values since the test mnemonic and test xprv
-	// are from different sources and should produce different entropy values.
-}
-
-func TestIdentityFromEntropy(t *testing.T) {
-	// Test that IdentityFromEntropy works with custom entropy
-	entropy := make([]byte, 32)
-	for i := range entropy {
-		entropy[i] = byte(i)
-	}
-
-	id, err := IdentityFromEntropy(entropy)
-	if err != nil {
-		t.Fatalf("identity from entropy: %v", err)
-	}
-
-	t.Logf("Custom entropy identity: %s", id.String())
-
-	// Test that it rejects wrong-sized entropy
-	_, err = IdentityFromEntropy(entropy[:31])
-	if err == nil {
-		t.Fatalf("expected error for 31-byte entropy")
-	}
-
-	// Create a 33-byte slice to test rejection
-	entropy33 := make([]byte, 33)
-	copy(entropy33, entropy)
-	_, err = IdentityFromEntropy(entropy33)
-	if err == nil {
-		t.Fatalf("expected error for 33-byte entropy")
-	}
-}
-
-func TestInvalidXPRV(t *testing.T) {
-	// Test with invalid xprv
-	_, err := DeriveIdentityFromXPRV("invalid-xprv", 0)
-	if err == nil {
-		t.Fatalf("expected error for invalid xprv")
-	}
-
-	t.Logf("Got expected error for invalid xprv: %v", err)
-}
diff --git a/internal/agehd/README.md b/pkg/agehd/README.md
similarity index 96%
rename from internal/agehd/README.md
rename to pkg/agehd/README.md
index ac4a065..c2c0309 100644
--- a/internal/agehd/README.md
+++ b/pkg/agehd/README.md
@@ -35,7 +35,7 @@ import (
     "fmt"
     "log"
     
-    "git.eeqj.de/sneak/secret/internal/agehd"
+    "git.eeqj.de/sneak/secret/pkg/agehd"
 )
 
 func main() {
@@ -61,7 +61,7 @@ import (
     "fmt"
     "log"
     
-    "git.eeqj.de/sneak/secret/internal/agehd"
+    "git.eeqj.de/sneak/secret/pkg/agehd"
 )
 
 func main() {
@@ -87,7 +87,7 @@ import (
     "fmt"
     "log"
     
-    "git.eeqj.de/sneak/secret/internal/agehd"
+    "git.eeqj.de/sneak/secret/pkg/agehd"
 )
 
 func main() {
@@ -114,7 +114,7 @@ import (
     "fmt"
     "log"
     
-    "git.eeqj.de/sneak/secret/internal/agehd"
+    "git.eeqj.de/sneak/secret/pkg/agehd"
 )
 
 func main() {
diff --git a/internal/agehd/agehd.go b/pkg/agehd/agehd.go
similarity index 98%
rename from internal/agehd/agehd.go
rename to pkg/agehd/agehd.go
index c58d4ff..6290782 100644
--- a/internal/agehd/agehd.go
+++ b/pkg/agehd/agehd.go
@@ -13,7 +13,7 @@ import (
 	"strings"
 
 	"filippo.io/age"
-	"git.eeqj.de/sneak/secret/internal/bip85"
+	"git.eeqj.de/sneak/secret/pkg/bip85"
 	"github.com/btcsuite/btcd/btcutil/hdkeychain"
 	"github.com/btcsuite/btcd/chaincfg"
 	"github.com/btcsuite/btcutil/bech32"
diff --git a/pkg/agehd/agehd_test.go b/pkg/agehd/agehd_test.go
new file mode 100644
index 0000000..2872f19
--- /dev/null
+++ b/pkg/agehd/agehd_test.go
@@ -0,0 +1,928 @@
+package agehd
+
+import (
+	"bytes"
+	"crypto/rand"
+	"fmt"
+	"io"
+	"strings"
+	"testing"
+
+	"filippo.io/age"
+	"github.com/tyler-smith/go-bip39"
+)
+
+const (
+	mnemonic = "abandon abandon abandon abandon abandon " +
+		"abandon abandon abandon abandon abandon abandon about"
+
+	// Test xprv from BIP85 test vectors
+	testXPRV = "xprv9s21ZrQH143K2LBWUUQRFXhucrQqBpKdRRxNVq2zBqsx8HVqFk2uYo8kmbaLLHRdqtQpUm98uKfu3vca1LqdGhUtyoFnCNkfmXRyPXLjbKb"
+
+	// Additional test mnemonics for comprehensive testing
+	testMnemonic12 = "abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon about"
+	testMnemonic15 = "abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon about"
+	testMnemonic18 = "abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon about"
+	testMnemonic21 = "abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon about"
+	testMnemonic24 = "abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon art"
+
+	// Test messages used throughout the tests
+	testMessageHelloWorld    = "hello world"
+	testMessageHelloFromXPRV = "hello from xprv"
+	testMessageGeneric       = "test message"
+	testMessageBoundary      = "boundary test"
+	testMessageBenchmark     = "benchmark test message"
+	testMessageLargePattern  = "A"
+
+	// Error messages for validation
+	errorMsgNeed32Bytes = "need 32-byte scalar, got"
+	errorMsgInvalidXPRV = "invalid-xprv"
+
+	// Test constants for various scenarios
+	testSkipMessage = "Skipping consistency test - test mnemonic and xprv are from different sources"
+
+	// Numeric constants for testing
+	testNumGoroutines = 10
+	testNumIterations = 100
+
+	// Large data test constants
+	testDataSizeMegabyte = 1024 * 1024 // 1 MB
+)
+
+func TestEncryptDecrypt(t *testing.T) {
+	id, err := DeriveIdentity(mnemonic, 0)
+	if err != nil {
+		t.Fatalf("derive: %v", err)
+	}
+
+	t.Logf("secret:    %s", id.String())
+	t.Logf("recipient: %s", id.Recipient().String())
+
+	var ct bytes.Buffer
+	w, err := age.Encrypt(&ct, id.Recipient())
+	if err != nil {
+		t.Fatalf("encrypt init: %v", err)
+	}
+	if _, err = io.WriteString(w, testMessageHelloWorld); err != nil {
+		t.Fatalf("write: %v", err)
+	}
+	if err = w.Close(); err != nil {
+		t.Fatalf("encrypt close: %v", err)
+	}
+
+	r, err := age.Decrypt(bytes.NewReader(ct.Bytes()), id)
+	if err != nil {
+		t.Fatalf("decrypt init: %v", err)
+	}
+	dec, err := io.ReadAll(r)
+	if err != nil {
+		t.Fatalf("read: %v", err)
+	}
+
+	if got := string(dec); got != testMessageHelloWorld {
+		t.Fatalf("round-trip mismatch: %q", got)
+	}
+}
+
+func TestDeriveIdentityFromXPRV(t *testing.T) {
+	id, err := DeriveIdentityFromXPRV(testXPRV, 0)
+	if err != nil {
+		t.Fatalf("derive from xprv: %v", err)
+	}
+
+	t.Logf("xprv secret:    %s", id.String())
+	t.Logf("xprv recipient: %s", id.Recipient().String())
+
+	// Test encryption/decryption with xprv-derived identity
+	var ct bytes.Buffer
+	w, err := age.Encrypt(&ct, id.Recipient())
+	if err != nil {
+		t.Fatalf("encrypt init: %v", err)
+	}
+	if _, err = io.WriteString(w, testMessageHelloFromXPRV); err != nil {
+		t.Fatalf("write: %v", err)
+	}
+	if err = w.Close(); err != nil {
+		t.Fatalf("encrypt close: %v", err)
+	}
+
+	r, err := age.Decrypt(bytes.NewReader(ct.Bytes()), id)
+	if err != nil {
+		t.Fatalf("decrypt init: %v", err)
+	}
+	dec, err := io.ReadAll(r)
+	if err != nil {
+		t.Fatalf("read: %v", err)
+	}
+
+	if got := string(dec); got != testMessageHelloFromXPRV {
+		t.Fatalf("round-trip mismatch: %q", got)
+	}
+}
+
+func TestDeterministicDerivation(t *testing.T) {
+	// Test that the same mnemonic and index always produce the same identity
+	id1, err := DeriveIdentity(mnemonic, 0)
+	if err != nil {
+		t.Fatalf("derive 1: %v", err)
+	}
+
+	id2, err := DeriveIdentity(mnemonic, 0)
+	if err != nil {
+		t.Fatalf("derive 2: %v", err)
+	}
+
+	if id1.String() != id2.String() {
+		t.Fatalf("identities should be deterministic: %s != %s", id1.String(), id2.String())
+	}
+
+	// Test that different indices produce different identities
+	id3, err := DeriveIdentity(mnemonic, 1)
+	if err != nil {
+		t.Fatalf("derive 3: %v", err)
+	}
+
+	if id1.String() == id3.String() {
+		t.Fatalf("different indices should produce different identities")
+	}
+
+	t.Logf("Index 0: %s", id1.String())
+	t.Logf("Index 1: %s", id3.String())
+}
+
+func TestDeterministicXPRVDerivation(t *testing.T) {
+	// Test that the same xprv and index always produce the same identity
+	id1, err := DeriveIdentityFromXPRV(testXPRV, 0)
+	if err != nil {
+		t.Fatalf("derive 1: %v", err)
+	}
+
+	id2, err := DeriveIdentityFromXPRV(testXPRV, 0)
+	if err != nil {
+		t.Fatalf("derive 2: %v", err)
+	}
+
+	if id1.String() != id2.String() {
+		t.Fatalf("xprv identities should be deterministic: %s != %s", id1.String(), id2.String())
+	}
+
+	// Test that different indices with same xprv produce different identities
+	id3, err := DeriveIdentityFromXPRV(testXPRV, 1)
+	if err != nil {
+		t.Fatalf("derive 3: %v", err)
+	}
+
+	if id1.String() == id3.String() {
+		t.Fatalf("different indices should produce different identities")
+	}
+
+	t.Logf("XPRV Index 0: %s", id1.String())
+	t.Logf("XPRV Index 1: %s", id3.String())
+}
+
+func TestMnemonicVsXPRVConsistency(t *testing.T) {
+	// Test that deriving from mnemonic and from the corresponding xprv produces the same result
+	// Note: This test is removed because the test mnemonic and test xprv are from different sources
+	// and are not expected to produce the same results.
+	t.Skip(testSkipMessage)
+}
+
+func TestEntropyLength(t *testing.T) {
+	// Test that DeriveEntropy returns exactly 32 bytes
+	entropy, err := DeriveEntropy(mnemonic, 0)
+	if err != nil {
+		t.Fatalf("derive entropy: %v", err)
+	}
+
+	if len(entropy) != 32 {
+		t.Fatalf("expected 32 bytes of entropy, got %d", len(entropy))
+	}
+
+	t.Logf("Entropy (32 bytes): %x", entropy)
+
+	// Test that DeriveEntropyFromXPRV returns exactly 32 bytes
+	entropyXPRV, err := DeriveEntropyFromXPRV(testXPRV, 0)
+	if err != nil {
+		t.Fatalf("derive entropy from xprv: %v", err)
+	}
+
+	if len(entropyXPRV) != 32 {
+		t.Fatalf("expected 32 bytes of entropy from xprv, got %d", len(entropyXPRV))
+	}
+
+	t.Logf("XPRV Entropy (32 bytes): %x", entropyXPRV)
+
+	// Note: We don't compare the entropy values since the test mnemonic and test xprv
+	// are from different sources and should produce different entropy values.
+}
+
+func TestIdentityFromEntropy(t *testing.T) {
+	// Test that IdentityFromEntropy works with custom entropy
+	entropy := make([]byte, 32)
+	for i := range entropy {
+		entropy[i] = byte(i)
+	}
+
+	id, err := IdentityFromEntropy(entropy)
+	if err != nil {
+		t.Fatalf("identity from entropy: %v", err)
+	}
+
+	t.Logf("Custom entropy identity: %s", id.String())
+
+	// Test that it rejects wrong-sized entropy
+	_, err = IdentityFromEntropy(entropy[:31])
+	if err == nil {
+		t.Fatalf("expected error for 31-byte entropy")
+	}
+
+	// Create a 33-byte slice to test rejection
+	entropy33 := make([]byte, 33)
+	copy(entropy33, entropy)
+	_, err = IdentityFromEntropy(entropy33)
+	if err == nil {
+		t.Fatalf("expected error for 33-byte entropy")
+	}
+}
+
+func TestInvalidXPRV(t *testing.T) {
+	// Test with invalid xprv
+	_, err := DeriveIdentityFromXPRV(errorMsgInvalidXPRV, 0)
+	if err == nil {
+		t.Fatalf("expected error for invalid xprv")
+	}
+
+	t.Logf("Got expected error for invalid xprv: %v", err)
+}
+
+// TestClampFunction tests the RFC-7748 clamping function
+func TestClampFunction(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    []byte
+		expected []byte
+	}{
+		{
+			name:     "all zeros",
+			input:    make([]byte, 32),
+			expected: []byte{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 64},
+		},
+		{
+			name:     "all ones",
+			input:    bytes.Repeat([]byte{255}, 32),
+			expected: append([]byte{248}, append(bytes.Repeat([]byte{255}, 30), 127)...),
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			input := make([]byte, 32)
+			copy(input, tt.input)
+			clamp(input)
+
+			// Check specific bits that should be clamped
+			if input[0]&7 != 0 {
+				t.Errorf("first byte should have bottom 3 bits cleared, got %08b", input[0])
+			}
+			if input[31]&128 != 0 {
+				t.Errorf("last byte should have top bit cleared, got %08b", input[31])
+			}
+			if input[31]&64 == 0 {
+				t.Errorf("last byte should have second-to-top bit set, got %08b", input[31])
+			}
+		})
+	}
+}
+
+// TestIdentityFromEntropyEdgeCases tests edge cases for IdentityFromEntropy
+func TestIdentityFromEntropyEdgeCases(t *testing.T) {
+	tests := []struct {
+		name        string
+		entropy     []byte
+		expectError bool
+		errorMsg    string
+	}{
+		{
+			name:        "nil entropy",
+			entropy:     nil,
+			expectError: true,
+			errorMsg:    errorMsgNeed32Bytes + " 0",
+		},
+		{
+			name:        "empty entropy",
+			entropy:     []byte{},
+			expectError: true,
+			errorMsg:    errorMsgNeed32Bytes + " 0",
+		},
+		{
+			name:        "too short entropy",
+			entropy:     make([]byte, 31),
+			expectError: true,
+			errorMsg:    errorMsgNeed32Bytes + " 31",
+		},
+		{
+			name:        "too long entropy",
+			entropy:     make([]byte, 33),
+			expectError: true,
+			errorMsg:    errorMsgNeed32Bytes + " 33",
+		},
+		{
+			name:        "valid 32-byte entropy",
+			entropy:     make([]byte, 32),
+			expectError: false,
+		},
+		{
+			name:        "random valid entropy",
+			entropy:     func() []byte { b := make([]byte, 32); rand.Read(b); return b }(),
+			expectError: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			identity, err := IdentityFromEntropy(tt.entropy)
+
+			if tt.expectError {
+				if err == nil {
+					t.Errorf("expected error but got none")
+				} else if !strings.Contains(err.Error(), tt.errorMsg) {
+					t.Errorf("expected error containing %q, got %q", tt.errorMsg, err.Error())
+				}
+				if identity != nil {
+					t.Errorf("expected nil identity on error, got %v", identity)
+				}
+			} else {
+				if err != nil {
+					t.Errorf("unexpected error: %v", err)
+				}
+				if identity == nil {
+					t.Errorf("expected valid identity, got nil")
+				}
+			}
+		})
+	}
+}
+
+// TestDeriveEntropyInvalidMnemonic tests error handling for invalid mnemonics
+func TestDeriveEntropyInvalidMnemonic(t *testing.T) {
+	tests := []struct {
+		name     string
+		mnemonic string
+	}{
+		{
+			name:     "empty mnemonic",
+			mnemonic: "",
+		},
+		{
+			name:     "single word",
+			mnemonic: "abandon",
+		},
+		{
+			name:     "invalid word",
+			mnemonic: "invalid word sequence that does not exist in bip39",
+		},
+		{
+			name:     "wrong word count",
+			mnemonic: "abandon abandon abandon abandon abandon",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			// Note: BIP39 library is quite permissive and doesn't validate
+			// mnemonic words strictly, so we mainly test that the function
+			// doesn't panic and produces some result
+			entropy, err := DeriveEntropy(tt.mnemonic, 0)
+			if err != nil {
+				t.Logf("Got error for invalid mnemonic %q: %v", tt.name, err)
+			} else {
+				if len(entropy) != 32 {
+					t.Errorf("expected 32 bytes even for invalid mnemonic, got %d", len(entropy))
+				}
+				t.Logf("Invalid mnemonic %q produced entropy: %x", tt.name, entropy)
+			}
+		})
+	}
+}
+
+// TestDeriveEntropyFromXPRVInvalidInputs tests error handling for invalid XPRVs
+func TestDeriveEntropyFromXPRVInvalidInputs(t *testing.T) {
+	tests := []struct {
+		name        string
+		xprv        string
+		expectError bool
+	}{
+		{
+			name:        "empty xprv",
+			xprv:        "",
+			expectError: true,
+		},
+		{
+			name:        "invalid base58",
+			xprv:        "invalid-base58-string-!@#$%",
+			expectError: true,
+		},
+		{
+			name:        "wrong prefix",
+			xprv:        "xpub661MyMwAqRbcFtXgS5sYJABqqG9YLmC4Q1Rdap9gSE8NqtwybGhePY2gZ29ESFjqJoCu1Rupje8YtGqsefD265TMg7usUDFdp6W1EGMcet8",
+			expectError: true,
+		},
+		{
+			name:        "truncated xprv",
+			xprv:        "xprv9s21ZrQH143K2LBWUUQRFXhucrQqBpKdRRxNVq2zBqsx8HVqFk2uYo8kmbaLLHRdqtQpUm98uKfu3vca1LqdGhUtyoFnCNkfmXRyPXLj",
+			expectError: true,
+		},
+		{
+			name:        "valid xprv",
+			xprv:        testXPRV,
+			expectError: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			entropy, err := DeriveEntropyFromXPRV(tt.xprv, 0)
+
+			if tt.expectError {
+				if err == nil {
+					t.Errorf("expected error for invalid xprv %q", tt.name)
+				} else {
+					t.Logf("Got expected error for %q: %v", tt.name, err)
+				}
+			} else {
+				if err != nil {
+					t.Errorf("unexpected error for valid xprv: %v", err)
+				}
+				if len(entropy) != 32 {
+					t.Errorf("expected 32 bytes of entropy, got %d", len(entropy))
+				}
+			}
+		})
+	}
+}
+
+// TestDifferentMnemonicLengths tests derivation with different mnemonic lengths
+func TestDifferentMnemonicLengths(t *testing.T) {
+	mnemonics := map[string]string{
+		"12 words": testMnemonic12,
+		"15 words": testMnemonic15,
+		"18 words": testMnemonic18,
+		"21 words": testMnemonic21,
+		"24 words": testMnemonic24,
+	}
+
+	for name, mnemonic := range mnemonics {
+		t.Run(name, func(t *testing.T) {
+			identity, err := DeriveIdentity(mnemonic, 0)
+			if err != nil {
+				t.Fatalf("failed to derive identity from %s: %v", name, err)
+			}
+
+			// Test that we can encrypt/decrypt
+			var ct bytes.Buffer
+			w, err := age.Encrypt(&ct, identity.Recipient())
+			if err != nil {
+				t.Fatalf("encrypt init: %v", err)
+			}
+			if _, err = io.WriteString(w, testMessageGeneric); err != nil {
+				t.Fatalf("write: %v", err)
+			}
+			if err = w.Close(); err != nil {
+				t.Fatalf("encrypt close: %v", err)
+			}
+
+			r, err := age.Decrypt(bytes.NewReader(ct.Bytes()), identity)
+			if err != nil {
+				t.Fatalf("decrypt init: %v", err)
+			}
+			dec, err := io.ReadAll(r)
+			if err != nil {
+				t.Fatalf("read: %v", err)
+			}
+
+			if string(dec) != testMessageGeneric {
+				t.Fatalf("round-trip failed for %s", name)
+			}
+
+			t.Logf("%s identity: %s", name, identity.String())
+		})
+	}
+}
+
+// TestIndexBoundaries tests derivation with various index values
+func TestIndexBoundaries(t *testing.T) {
+	indices := []uint32{
+		0,          // minimum
+		1,          // basic
+		100,        // moderate
+		1000,       // larger
+		0x7FFFFFFF, // maximum hardened index
+		0xFFFFFFFF, // maximum uint32
+	}
+
+	for _, index := range indices {
+		t.Run(fmt.Sprintf("index_%d", index), func(t *testing.T) {
+			identity, err := DeriveIdentity(mnemonic, index)
+			if err != nil {
+				t.Fatalf("failed to derive identity at index %d: %v", index, err)
+			}
+
+			// Verify the identity is valid by testing encryption/decryption
+			var ct bytes.Buffer
+			w, err := age.Encrypt(&ct, identity.Recipient())
+			if err != nil {
+				t.Fatalf("encrypt init at index %d: %v", index, err)
+			}
+			if _, err = io.WriteString(w, testMessageBoundary); err != nil {
+				t.Fatalf("write at index %d: %v", index, err)
+			}
+			if err = w.Close(); err != nil {
+				t.Fatalf("encrypt close at index %d: %v", index, err)
+			}
+
+			r, err := age.Decrypt(bytes.NewReader(ct.Bytes()), identity)
+			if err != nil {
+				t.Fatalf("decrypt init at index %d: %v", index, err)
+			}
+			dec, err := io.ReadAll(r)
+			if err != nil {
+				t.Fatalf("read at index %d: %v", index, err)
+			}
+
+			if string(dec) != testMessageBoundary {
+				t.Fatalf("round-trip failed at index %d", index)
+			}
+
+			t.Logf("Index %d identity: %s", index, identity.String())
+		})
+	}
+}
+
+// TestEntropyUniqueness tests that different inputs produce different entropy
+func TestEntropyUniqueness(t *testing.T) {
+	// Test different indices with same mnemonic
+	entropy1, err := DeriveEntropy(mnemonic, 0)
+	if err != nil {
+		t.Fatalf("derive entropy 1: %v", err)
+	}
+
+	entropy2, err := DeriveEntropy(mnemonic, 1)
+	if err != nil {
+		t.Fatalf("derive entropy 2: %v", err)
+	}
+
+	if bytes.Equal(entropy1, entropy2) {
+		t.Fatalf("different indices should produce different entropy")
+	}
+
+	// Test different mnemonics with same index
+	entropy3, err := DeriveEntropy(testMnemonic24, 0)
+	if err != nil {
+		t.Fatalf("derive entropy 3: %v", err)
+	}
+
+	if bytes.Equal(entropy1, entropy3) {
+		t.Fatalf("different mnemonics should produce different entropy")
+	}
+
+	t.Logf("Entropy uniqueness verified across indices and mnemonics")
+}
+
+// TestConcurrentDerivation tests that derivation is safe for concurrent use
+func TestConcurrentDerivation(t *testing.T) {
+	results := make(chan string, testNumGoroutines*testNumIterations)
+	errors := make(chan error, testNumGoroutines*testNumIterations)
+
+	for i := 0; i < testNumGoroutines; i++ {
+		go func(goroutineID int) {
+			for j := 0; j < testNumIterations; j++ {
+				identity, err := DeriveIdentity(mnemonic, uint32(j))
+				if err != nil {
+					errors <- err
+					return
+				}
+				results <- identity.String()
+			}
+		}(i)
+	}
+
+	// Collect results
+	resultMap := make(map[string]int)
+	for i := 0; i < testNumGoroutines*testNumIterations; i++ {
+		select {
+		case result := <-results:
+			resultMap[result]++
+		case err := <-errors:
+			t.Fatalf("concurrent derivation error: %v", err)
+		}
+	}
+
+	// Verify that each index produced the same result across all goroutines
+	expectedResults := testNumGoroutines
+	for result, count := range resultMap {
+		if count != expectedResults {
+			t.Errorf("result %s appeared %d times, expected %d", result, count, expectedResults)
+		}
+	}
+
+	t.Logf("Concurrent derivation test passed with %d unique results", len(resultMap))
+}
+
+// Benchmark tests
+func BenchmarkDeriveIdentity(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		_, err := DeriveIdentity(mnemonic, uint32(i%1000))
+		if err != nil {
+			b.Fatalf("derive identity: %v", err)
+		}
+	}
+}
+
+func BenchmarkDeriveIdentityFromXPRV(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		_, err := DeriveIdentityFromXPRV(testXPRV, uint32(i%1000))
+		if err != nil {
+			b.Fatalf("derive identity from xprv: %v", err)
+		}
+	}
+}
+
+func BenchmarkDeriveEntropy(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		_, err := DeriveEntropy(mnemonic, uint32(i%1000))
+		if err != nil {
+			b.Fatalf("derive entropy: %v", err)
+		}
+	}
+}
+
+func BenchmarkIdentityFromEntropy(b *testing.B) {
+	entropy := make([]byte, 32)
+	rand.Read(entropy)
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		_, err := IdentityFromEntropy(entropy)
+		if err != nil {
+			b.Fatalf("identity from entropy: %v", err)
+		}
+	}
+}
+
+func BenchmarkEncryptDecrypt(b *testing.B) {
+	identity, err := DeriveIdentity(mnemonic, 0)
+	if err != nil {
+		b.Fatalf("derive identity: %v", err)
+	}
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		var ct bytes.Buffer
+		w, err := age.Encrypt(&ct, identity.Recipient())
+		if err != nil {
+			b.Fatalf("encrypt init: %v", err)
+		}
+		if _, err = io.WriteString(w, testMessageBenchmark); err != nil {
+			b.Fatalf("write: %v", err)
+		}
+		if err = w.Close(); err != nil {
+			b.Fatalf("encrypt close: %v", err)
+		}
+
+		r, err := age.Decrypt(bytes.NewReader(ct.Bytes()), identity)
+		if err != nil {
+			b.Fatalf("decrypt init: %v", err)
+		}
+		_, err = io.ReadAll(r)
+		if err != nil {
+			b.Fatalf("read: %v", err)
+		}
+	}
+}
+
+// TestConstants verifies the hardcoded constants
+func TestConstants(t *testing.T) {
+	if purpose != 83696968 {
+		t.Errorf("purpose constant mismatch: expected 83696968, got %d", purpose)
+	}
+	if vendorID != 592366788 {
+		t.Errorf("vendorID constant mismatch: expected 592366788, got %d", vendorID)
+	}
+	if appID != 733482323 {
+		t.Errorf("appID constant mismatch: expected 733482323, got %d", appID)
+	}
+	if hrp != "age-secret-key-" {
+		t.Errorf("hrp constant mismatch: expected 'age-secret-key-', got %q", hrp)
+	}
+}
+
+// TestIdentityStringFormat tests that generated identities have the correct format
+func TestIdentityStringFormat(t *testing.T) {
+	identity, err := DeriveIdentity(mnemonic, 0)
+	if err != nil {
+		t.Fatalf("derive identity: %v", err)
+	}
+
+	secretKey := identity.String()
+	recipient := identity.Recipient().String()
+
+	// Check secret key format
+	if !strings.HasPrefix(secretKey, "AGE-SECRET-KEY-") {
+		t.Errorf("secret key should start with 'AGE-SECRET-KEY-', got: %s", secretKey)
+	}
+
+	// Check recipient format
+	if !strings.HasPrefix(recipient, "age1") {
+		t.Errorf("recipient should start with 'age1', got: %s", recipient)
+	}
+
+	// Check that they're different
+	if secretKey == recipient {
+		t.Errorf("secret key and recipient should be different")
+	}
+
+	t.Logf("Secret key format: %s", secretKey)
+	t.Logf("Recipient format: %s", recipient)
+}
+
+// TestLargeMessageEncryption tests encryption/decryption of larger messages
+func TestLargeMessageEncryption(t *testing.T) {
+	identity, err := DeriveIdentity(mnemonic, 0)
+	if err != nil {
+		t.Fatalf("derive identity: %v", err)
+	}
+
+	// Test with different message sizes
+	sizes := []int{1, 100, 1024, 10240, 100000}
+
+	for _, size := range sizes {
+		t.Run(fmt.Sprintf("size_%d", size), func(t *testing.T) {
+			message := strings.Repeat(testMessageLargePattern, size)
+
+			var ct bytes.Buffer
+			w, err := age.Encrypt(&ct, identity.Recipient())
+			if err != nil {
+				t.Fatalf("encrypt init: %v", err)
+			}
+			if _, err = io.WriteString(w, message); err != nil {
+				t.Fatalf("write: %v", err)
+			}
+			if err = w.Close(); err != nil {
+				t.Fatalf("encrypt close: %v", err)
+			}
+
+			r, err := age.Decrypt(bytes.NewReader(ct.Bytes()), identity)
+			if err != nil {
+				t.Fatalf("decrypt init: %v", err)
+			}
+			dec, err := io.ReadAll(r)
+			if err != nil {
+				t.Fatalf("read: %v", err)
+			}
+
+			if string(dec) != message {
+				t.Fatalf("message size %d: round-trip failed", size)
+			}
+
+			t.Logf("Successfully encrypted/decrypted %d byte message", size)
+		})
+	}
+}
+
+// TestRandomMnemonicDeterministicGeneration tests that:
+// 1. A random mnemonic generates the same keys deterministically
+// 2. Large data (1MB) can be encrypted and decrypted successfully
+func TestRandomMnemonicDeterministicGeneration(t *testing.T) {
+	// Generate a random mnemonic using the BIP39 library
+	entropy := make([]byte, 32) // 256 bits for 24-word mnemonic
+	_, err := rand.Read(entropy)
+	if err != nil {
+		t.Fatalf("failed to generate random entropy: %v", err)
+	}
+
+	randomMnemonic, err := bip39.NewMnemonic(entropy)
+	if err != nil {
+		t.Fatalf("failed to generate random mnemonic: %v", err)
+	}
+
+	t.Logf("Generated random mnemonic: %s", randomMnemonic)
+
+	// Test index for key derivation
+	testIndex := uint32(42)
+
+	// Generate the first identity
+	identity1, err := DeriveIdentity(randomMnemonic, testIndex)
+	if err != nil {
+		t.Fatalf("failed to derive first identity: %v", err)
+	}
+
+	// Generate the second identity with the same mnemonic and index
+	identity2, err := DeriveIdentity(randomMnemonic, testIndex)
+	if err != nil {
+		t.Fatalf("failed to derive second identity: %v", err)
+	}
+
+	// Verify that both private keys are identical
+	privateKey1 := identity1.String()
+	privateKey2 := identity2.String()
+	if privateKey1 != privateKey2 {
+		t.Fatalf("private keys should be identical:\nFirst:  %s\nSecond: %s", privateKey1, privateKey2)
+	}
+
+	// Verify that both public keys (recipients) are identical
+	publicKey1 := identity1.Recipient().String()
+	publicKey2 := identity2.Recipient().String()
+	if publicKey1 != publicKey2 {
+		t.Fatalf("public keys should be identical:\nFirst:  %s\nSecond: %s", publicKey1, publicKey2)
+	}
+
+	t.Logf("✓ Deterministic generation verified")
+	t.Logf("Private key: %s", privateKey1)
+	t.Logf("Public key:  %s", publicKey1)
+
+	// Generate 1 MB of random data for encryption test
+	testData := make([]byte, testDataSizeMegabyte)
+	_, err = rand.Read(testData)
+	if err != nil {
+		t.Fatalf("failed to generate random test data: %v", err)
+	}
+
+	t.Logf("Generated %d bytes of random test data", len(testData))
+
+	// Encrypt the data using the public key (recipient)
+	var ciphertext bytes.Buffer
+	encryptor, err := age.Encrypt(&ciphertext, identity1.Recipient())
+	if err != nil {
+		t.Fatalf("failed to create encryptor: %v", err)
+	}
+
+	_, err = encryptor.Write(testData)
+	if err != nil {
+		t.Fatalf("failed to write data to encryptor: %v", err)
+	}
+
+	err = encryptor.Close()
+	if err != nil {
+		t.Fatalf("failed to close encryptor: %v", err)
+	}
+
+	t.Logf("✓ Encrypted %d bytes into %d bytes of ciphertext", len(testData), ciphertext.Len())
+
+	// Decrypt the data using the private key
+	decryptor, err := age.Decrypt(bytes.NewReader(ciphertext.Bytes()), identity1)
+	if err != nil {
+		t.Fatalf("failed to create decryptor: %v", err)
+	}
+
+	decryptedData, err := io.ReadAll(decryptor)
+	if err != nil {
+		t.Fatalf("failed to read decrypted data: %v", err)
+	}
+
+	t.Logf("✓ Decrypted %d bytes", len(decryptedData))
+
+	// Verify that the decrypted data matches the original
+	if len(decryptedData) != len(testData) {
+		t.Fatalf("decrypted data length mismatch: expected %d, got %d", len(testData), len(decryptedData))
+	}
+
+	if !bytes.Equal(testData, decryptedData) {
+		t.Fatalf("decrypted data does not match original data")
+	}
+
+	t.Logf("✓ Large data encryption/decryption test passed successfully")
+
+	// Additional verification: test with the second identity (should work identically)
+	var ciphertext2 bytes.Buffer
+	encryptor2, err := age.Encrypt(&ciphertext2, identity2.Recipient())
+	if err != nil {
+		t.Fatalf("failed to create second encryptor: %v", err)
+	}
+
+	_, err = encryptor2.Write(testData)
+	if err != nil {
+		t.Fatalf("failed to write data to second encryptor: %v", err)
+	}
+
+	err = encryptor2.Close()
+	if err != nil {
+		t.Fatalf("failed to close second encryptor: %v", err)
+	}
+
+	// Decrypt with the second identity
+	decryptor2, err := age.Decrypt(bytes.NewReader(ciphertext2.Bytes()), identity2)
+	if err != nil {
+		t.Fatalf("failed to create second decryptor: %v", err)
+	}
+
+	decryptedData2, err := io.ReadAll(decryptor2)
+	if err != nil {
+		t.Fatalf("failed to read second decrypted data: %v", err)
+	}
+
+	if !bytes.Equal(testData, decryptedData2) {
+		t.Fatalf("second decrypted data does not match original data")
+	}
+
+	t.Logf("✓ Cross-verification with second identity successful")
+}
diff --git a/internal/bip85/README.md b/pkg/bip85/README.md
similarity index 97%
rename from internal/bip85/README.md
rename to pkg/bip85/README.md
index 03f8e19..018d924 100644
--- a/internal/bip85/README.md
+++ b/pkg/bip85/README.md
@@ -17,7 +17,7 @@ BIP85 enables a variety of use cases:
 ```go
 import (
     "fmt"
-    "git.eeqj.de/sneak/secret/internal/bip85"
+    "git.eeqj.de/sneak/secret/pkg/bip85"
     "github.com/btcsuite/btcd/btcutil/hdkeychain"
 )
 
@@ -140,7 +140,7 @@ The implementation is also compatible with the Python reference implementation's
 Run the tests with verbose output to see the test vectors and results:
 
 ```
-go test -v git.eeqj.de/sneak/secret/internal/bip85
+go test -v git.eeqj.de/sneak/secret/pkg/bip85
 ```
 
 ## References
diff --git a/internal/bip85/bip-0085.mediawiki b/pkg/bip85/bip-0085.mediawiki
similarity index 100%
rename from internal/bip85/bip-0085.mediawiki
rename to pkg/bip85/bip-0085.mediawiki
diff --git a/internal/bip85/bip85.go b/pkg/bip85/bip85.go
similarity index 100%
rename from internal/bip85/bip85.go
rename to pkg/bip85/bip85.go
diff --git a/internal/bip85/bip85_test.go b/pkg/bip85/bip85_test.go
similarity index 100%
rename from internal/bip85/bip85_test.go
rename to pkg/bip85/bip85_test.go
diff --git a/test_secret_manager.sh b/test_secret_manager.sh
new file mode 100755
index 0000000..9820d69
--- /dev/null
+++ b/test_secret_manager.sh
@@ -0,0 +1,785 @@
+#!/bin/bash
+
+set -e  # Exit on any error
+
+# Colors for output
+RED='\033[0;31m'
+GREEN='\033[0;32m'
+YELLOW='\033[1;33m'
+BLUE='\033[0;34m'
+NC='\033[0m' # No Color
+
+# Test configuration
+TEST_MNEMONIC="abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon about"
+TEST_PASSPHRASE="test-passphrase-123"
+TEMP_DIR="$(mktemp -d)"
+SECRET_BINARY="./secret"
+
+echo -e "${BLUE}=== Secret Manager Comprehensive Test Script ===${NC}"
+echo -e "${YELLOW}Using temporary directory: $TEMP_DIR${NC}"
+
+# Function to print test steps
+print_step() {
+    echo -e "\n${BLUE}Step $1: $2${NC}"
+}
+
+# Function to print success
+print_success() {
+    echo -e "${GREEN}✓ $1${NC}"
+}
+
+# Function to print error and exit
+print_error() {
+    echo -e "${RED}✗ $1${NC}"
+    exit 1
+}
+
+# Function to print warning (for expected failures)
+print_warning() {
+    echo -e "${YELLOW}⚠ $1${NC}"
+}
+
+# Function to clear state directory and reset environment
+reset_state() {
+    echo -e "${YELLOW}Resetting state directory...${NC}"
+    
+    # Safety checks before removing anything
+    if [ -z "$TEMP_DIR" ]; then
+        print_error "TEMP_DIR is not set, cannot reset state safely"
+    fi
+    
+    if [ ! -d "$TEMP_DIR" ]; then
+        print_error "TEMP_DIR ($TEMP_DIR) is not a directory, cannot reset state safely"
+    fi
+    
+    # Additional safety: ensure TEMP_DIR looks like a temp directory
+    case "$TEMP_DIR" in
+        /tmp/* | /var/folders/* | */tmp/*)
+            # Looks like a reasonable temp directory path
+            ;;
+        *)
+            print_error "TEMP_DIR ($TEMP_DIR) does not look like a safe temporary directory path"
+            ;;
+    esac
+    
+    # Now it's safe to remove contents - use find to avoid glob expansion issues
+    find "${TEMP_DIR:?}" -mindepth 1 -delete 2>/dev/null || true
+    unset SB_SECRET_MNEMONIC
+    unset SB_UNLOCK_PASSPHRASE
+    export SB_SECRET_STATE_DIR="$TEMP_DIR"
+}
+
+# Cleanup function
+cleanup() {
+    echo -e "\n${YELLOW}Cleaning up...${NC}"
+    rm -rf "$TEMP_DIR"
+    unset SB_SECRET_STATE_DIR
+    unset SB_SECRET_MNEMONIC
+    unset SB_UNLOCK_PASSPHRASE
+    echo -e "${GREEN}Cleanup complete${NC}"
+}
+
+# Set cleanup trap
+trap cleanup EXIT
+
+# Build the secret binary if it doesn't exist
+if [ ! -f "$SECRET_BINARY" ]; then
+    print_step "0" "Building secret binary"
+    go build -o "$SECRET_BINARY" ./cmd/secret/
+    print_success "Built secret binary"
+fi
+
+# Test 1: Set up environment variables
+print_step "1" "Setting up environment variables"
+export SB_SECRET_STATE_DIR="$TEMP_DIR"
+export SB_SECRET_MNEMONIC="$TEST_MNEMONIC"
+print_success "Environment variables set"
+echo "  SB_SECRET_STATE_DIR=$SB_SECRET_STATE_DIR"
+echo "  SB_SECRET_MNEMONIC=$TEST_MNEMONIC"
+
+# Test 2: Initialize the secret manager (should create default vault)
+print_step "2" "Initializing secret manager (creates default vault)"
+# Set passphrase for init command only
+export SB_UNLOCK_PASSPHRASE="$TEST_PASSPHRASE"
+if $SECRET_BINARY init > /dev/null 2>&1; then
+    print_success "Secret manager initialized with default vault"
+else
+    print_error "Failed to initialize secret manager"
+fi
+# Unset passphrase after init
+unset SB_UNLOCK_PASSPHRASE
+
+# Verify directory structure was created
+if [ -d "$TEMP_DIR" ]; then
+    print_success "State directory created: $TEMP_DIR"
+else
+    print_error "State directory was not created"
+fi
+
+# Test 3: Vault management
+print_step "3" "Testing vault management"
+
+# List vaults (should show default)
+echo "Listing vaults..."
+if $SECRET_BINARY vault list > /dev/null 2>&1; then
+    VAULTS=$($SECRET_BINARY vault list)
+    echo "Available vaults: $VAULTS"
+    print_success "Listed vaults successfully"
+else
+    print_error "Failed to list vaults"
+fi
+
+# Create a new vault
+echo "Creating new vault 'work'..."
+if $SECRET_BINARY vault create work > /dev/null 2>&1; then
+    print_success "Created vault 'work'"
+else
+    print_error "Failed to create vault 'work'"
+fi
+
+# Create another vault
+echo "Creating new vault 'personal'..."
+if $SECRET_BINARY vault create personal > /dev/null 2>&1; then
+    print_success "Created vault 'personal'"
+else
+    print_error "Failed to create vault 'personal'"
+fi
+
+# List vaults again (should show default, work, personal)
+echo "Listing vaults after creation..."
+if $SECRET_BINARY vault list > /dev/null 2>&1; then
+    VAULTS=$($SECRET_BINARY vault list)
+    echo "Available vaults: $VAULTS"
+    print_success "Listed vaults after creation"
+else
+    print_error "Failed to list vaults after creation"
+fi
+
+# Switch to work vault
+echo "Switching to 'work' vault..."
+if $SECRET_BINARY vault select work > /dev/null 2>&1; then
+    print_success "Switched to 'work' vault"
+else
+    print_error "Failed to switch to 'work' vault"
+fi
+
+# Test 4: Import functionality with different environment variable combinations
+print_step "4" "Testing import functionality with different environment variable combinations"
+
+# Test 4a: Import with mnemonic env var set, no passphrase env var
+echo -e "\n${YELLOW}Test 4a: Import with SB_SECRET_MNEMONIC set, SB_UNLOCK_PASSPHRASE unset${NC}"
+reset_state
+export SB_SECRET_MNEMONIC="$TEST_MNEMONIC"
+
+# Create a vault first
+if $SECRET_BINARY vault create test-vault > /dev/null 2>&1; then
+    print_success "Created test-vault for import testing"
+else
+    print_error "Failed to create test-vault"
+fi
+
+# Import should prompt for passphrase
+echo "Importing with mnemonic env var set, should prompt for passphrase..."
+if echo "$TEST_PASSPHRASE" | $SECRET_BINARY import test-vault > /dev/null 2>&1; then
+    print_success "Import succeeded with mnemonic env var (prompted for passphrase)"
+else
+    print_error "Import failed with mnemonic env var"
+fi
+
+# Test 4b: Import with passphrase env var set, no mnemonic env var
+echo -e "\n${YELLOW}Test 4b: Import with SB_UNLOCK_PASSPHRASE set, SB_SECRET_MNEMONIC unset${NC}"
+reset_state
+export SB_UNLOCK_PASSPHRASE="$TEST_PASSPHRASE"
+
+# Create a vault first
+if $SECRET_BINARY vault create test-vault2 > /dev/null 2>&1; then
+    print_success "Created test-vault2 for import testing"
+else
+    print_error "Failed to create test-vault2"
+fi
+
+# Import should prompt for mnemonic
+echo "Importing with passphrase env var set, should prompt for mnemonic..."
+if echo "$TEST_MNEMONIC" | $SECRET_BINARY import test-vault2 > /dev/null 2>&1; then
+    print_success "Import succeeded with passphrase env var (prompted for mnemonic)"
+else
+    print_error "Import failed with passphrase env var"
+fi
+
+# Test 4c: Import with both env vars set
+echo -e "\n${YELLOW}Test 4c: Import with both SB_SECRET_MNEMONIC and SB_UNLOCK_PASSPHRASE set${NC}"
+reset_state
+export SB_SECRET_MNEMONIC="$TEST_MNEMONIC"
+export SB_UNLOCK_PASSPHRASE="$TEST_PASSPHRASE"
+
+# Create a vault first
+if $SECRET_BINARY vault create test-vault3 > /dev/null 2>&1; then
+    print_success "Created test-vault3 for import testing"
+else
+    print_error "Failed to create test-vault3"
+fi
+
+# Import should not prompt for anything
+echo "Importing with both env vars set, should not prompt..."
+if $SECRET_BINARY import test-vault3 > /dev/null 2>&1; then
+    print_success "Import succeeded with both env vars (no prompts)"
+else
+    print_error "Import failed with both env vars"
+fi
+
+# Test 4d: Import with neither env var set
+echo -e "\n${YELLOW}Test 4d: Import with neither SB_SECRET_MNEMONIC nor SB_UNLOCK_PASSPHRASE set${NC}"
+reset_state
+
+# Create a vault first
+if $SECRET_BINARY vault create test-vault4 > /dev/null 2>&1; then
+    print_success "Created test-vault4 for import testing"
+else
+    print_error "Failed to create test-vault4"
+fi
+
+# Import should prompt for both mnemonic and passphrase
+echo "Importing with neither env var set, should prompt for both..."
+if expect -c "
+    spawn $SECRET_BINARY import test-vault4
+    expect \"Enter your BIP39 mnemonic phrase:\"
+    send \"$TEST_MNEMONIC\n\"
+    expect \"Enter passphrase for unlock key:\"
+    send \"$TEST_PASSPHRASE\n\"
+    expect \"Confirm passphrase:\"
+    send \"$TEST_PASSPHRASE\n\"
+    expect eof
+" > /dev/null 2>&1; then
+    print_success "Import succeeded with no env vars (prompted for both)"
+else
+    print_error "Import failed with no env vars"
+fi
+
+# Test 4e: Import into non-existent vault (should fail)
+echo -e "\n${YELLOW}Test 4e: Import into non-existent vault (should fail)${NC}"
+reset_state
+export SB_SECRET_MNEMONIC="$TEST_MNEMONIC"
+export SB_UNLOCK_PASSPHRASE="$TEST_PASSPHRASE"
+
+echo "Importing into non-existent vault (should fail)..."
+if $SECRET_BINARY import nonexistent-vault > /dev/null 2>&1; then
+    print_error "Import should have failed for non-existent vault"
+else
+    print_success "Import correctly failed for non-existent vault"
+fi
+
+# Test 4f: Import with invalid mnemonic (should fail)
+echo -e "\n${YELLOW}Test 4f: Import with invalid mnemonic (should fail)${NC}"
+reset_state
+export SB_SECRET_MNEMONIC="invalid mnemonic phrase that should not work"
+export SB_UNLOCK_PASSPHRASE="$TEST_PASSPHRASE"
+
+# Create a vault first
+if $SECRET_BINARY vault create test-vault5 > /dev/null 2>&1; then
+    print_success "Created test-vault5 for invalid mnemonic testing"
+else
+    print_error "Failed to create test-vault5"
+fi
+
+echo "Importing with invalid mnemonic (should fail)..."
+if $SECRET_BINARY import test-vault5 > /dev/null 2>&1; then
+    print_error "Import should have failed with invalid mnemonic"
+else
+    print_success "Import correctly failed with invalid mnemonic"
+fi
+
+# Reset state for remaining tests
+reset_state
+export SB_SECRET_MNEMONIC="$TEST_MNEMONIC"
+
+# Test 5: Original import functionality test (using mnemonic-based)
+print_step "5" "Testing original import functionality"
+
+# Initialize to create default vault
+if (echo "$TEST_PASSPHRASE"; echo "$TEST_PASSPHRASE") | $SECRET_BINARY init > /dev/null 2>&1; then
+    print_success "Initialized for Step 5 testing"
+else
+    print_error "Failed to initialize for Step 5 testing"
+fi
+
+# Create work vault for import testing
+if $SECRET_BINARY vault create work > /dev/null 2>&1; then
+    print_success "Created work vault for import testing"
+else
+    print_error "Failed to create work vault"
+fi
+
+# Switch to work vault
+echo "Switching to 'work' vault..."
+if $SECRET_BINARY vault select work > /dev/null 2>&1; then
+    print_success "Switched to 'work' vault"
+else
+    print_error "Failed to switch to 'work' vault"
+fi
+
+# Import into work vault using mnemonic (should derive long-term key)
+echo "Importing mnemonic into 'work' vault..."
+# Set passphrase for import command only
+export SB_UNLOCK_PASSPHRASE="$TEST_PASSPHRASE"
+if $SECRET_BINARY import work > /dev/null 2>&1; then
+    print_success "Imported mnemonic into 'work' vault"
+else
+    print_error "Failed to import mnemonic into 'work' vault"
+fi
+# Unset passphrase after import
+unset SB_UNLOCK_PASSPHRASE
+
+# Switch back to default vault
+echo "Switching back to 'default' vault..."
+if $SECRET_BINARY vault select default > /dev/null 2>&1; then
+    print_success "Switched back to 'default' vault"
+else
+    print_error "Failed to switch back to 'default' vault"
+fi
+
+# Test 6: Unlock key management
+print_step "6" "Testing unlock key management"
+
+# Create passphrase-protected unlock key
+echo "Creating passphrase-protected unlock key..."
+# Note: This test uses stdin input instead of environment variable to test the traditional approach
+if echo "$TEST_PASSPHRASE" | $SECRET_BINARY keys add passphrase > /dev/null 2>&1; then
+    print_success "Created passphrase-protected unlock key"
+else
+    print_error "Failed to create passphrase-protected unlock key"
+fi
+
+# List unlock keys
+echo "Listing unlock keys..."
+if $SECRET_BINARY keys list > /dev/null 2>&1; then
+    KEYS=$($SECRET_BINARY keys list)
+    echo "Available unlock keys: $KEYS"
+    print_success "Listed unlock keys"
+else
+    print_error "Failed to list unlock keys"
+fi
+
+# Test 7: Secret management with mnemonic (keyless operation)
+print_step "7" "Testing mnemonic-based secret operations (keyless)"
+
+# Add secrets using mnemonic (no unlock key required)
+echo "Adding secrets using mnemonic-based long-term key..."
+
+# Test secret 1
+if echo "my-super-secret-password" | $SECRET_BINARY add "database/password" > /dev/null 2>&1; then
+    print_success "Added secret: database/password"
+else
+    print_error "Failed to add secret: database/password"
+fi
+
+# Test secret 2
+if echo "api-key-12345" | $SECRET_BINARY add "api/key" > /dev/null 2>&1; then
+    print_success "Added secret: api/key"
+else
+    print_error "Failed to add secret: api/key"
+fi
+
+# Test secret 3 (with path)
+if echo "ssh-private-key-content" | $SECRET_BINARY add "ssh/private-key" > /dev/null 2>&1; then
+    print_success "Added secret: ssh/private-key"
+else
+    print_error "Failed to add secret: ssh/private-key"
+fi
+
+# Test secret 4 (with dots and underscores)
+if echo "jwt-secret-token" | $SECRET_BINARY add "app.config_jwt_secret" > /dev/null 2>&1; then
+    print_success "Added secret: app.config_jwt_secret"
+else
+    print_error "Failed to add secret: app.config_jwt_secret"
+fi
+
+# Retrieve secrets using mnemonic
+echo "Retrieving secrets using mnemonic-based long-term key..."
+
+# Retrieve and verify secret 1
+RETRIEVED_SECRET1=$($SECRET_BINARY get "database/password" 2>/dev/null)
+if [ "$RETRIEVED_SECRET1" = "my-super-secret-password" ]; then
+    print_success "Retrieved and verified secret: database/password"
+else
+    print_error "Failed to retrieve or verify secret: database/password"
+fi
+
+# Retrieve and verify secret 2
+RETRIEVED_SECRET2=$($SECRET_BINARY get "api/key" 2>/dev/null)
+if [ "$RETRIEVED_SECRET2" = "api-key-12345" ]; then
+    print_success "Retrieved and verified secret: api/key"
+else
+    print_error "Failed to retrieve or verify secret: api/key"
+fi
+
+# Retrieve and verify secret 3
+RETRIEVED_SECRET3=$($SECRET_BINARY get "ssh/private-key" 2>/dev/null)
+if [ "$RETRIEVED_SECRET3" = "ssh-private-key-content" ]; then
+    print_success "Retrieved and verified secret: ssh/private-key"
+else
+    print_error "Failed to retrieve or verify secret: ssh/private-key"
+fi
+
+# List all secrets
+echo "Listing all secrets..."
+if $SECRET_BINARY list > /dev/null 2>&1; then
+    SECRETS=$($SECRET_BINARY list)
+    echo "Secrets in current vault:"
+    echo "$SECRETS" | while read -r secret; do
+        echo "  - $secret"
+    done
+    print_success "Listed all secrets"
+else
+    print_error "Failed to list secrets"
+fi
+
+# Test 8: Secret management without mnemonic (traditional unlock key approach)
+print_step "8" "Testing traditional unlock key approach"
+
+# Temporarily unset mnemonic to test traditional approach
+unset SB_SECRET_MNEMONIC
+
+# Add a secret using traditional unlock key approach
+echo "Adding secret using traditional unlock key..."
+if echo "traditional-secret-value" | $SECRET_BINARY add "traditional/secret" > /dev/null 2>&1; then
+    print_success "Added secret using traditional approach: traditional/secret"
+else
+    print_error "Failed to add secret using traditional approach"
+fi
+
+# Retrieve secret using traditional unlock key approach
+RETRIEVED_TRADITIONAL=$($SECRET_BINARY get "traditional/secret" 2>/dev/null)
+if [ "$RETRIEVED_TRADITIONAL" = "traditional-secret-value" ]; then
+    print_success "Retrieved and verified traditional secret: traditional/secret"
+else
+    print_error "Failed to retrieve or verify traditional secret"
+fi
+
+# Test 9: Advanced unlock key management
+print_step "9" "Testing advanced unlock key management"
+
+# Re-enable mnemonic for key operations
+export SB_SECRET_MNEMONIC="$TEST_MNEMONIC"
+
+# Create PGP unlock key (if GPG is available)
+echo "Testing PGP unlock key creation..."
+if command -v gpg >/dev/null 2>&1; then
+    # This would require a GPG key ID - for testing we'll just check the command exists
+    if $SECRET_BINARY keys add pgp --help > /dev/null 2>&1; then
+        print_success "PGP unlock key command available"
+    else
+        print_warning "PGP unlock key command not yet implemented"
+    fi
+else
+    print_warning "GPG not available for PGP unlock key testing"
+fi
+
+# Test Secure Enclave (macOS only)
+if [[ "$OSTYPE" == "darwin"* ]]; then
+    echo "Testing Secure Enclave unlock key creation..."
+    if $SECRET_BINARY enroll sep > /dev/null 2>&1; then
+        print_success "Created Secure Enclave unlock key"
+    else
+        print_warning "Secure Enclave unlock key creation not yet implemented"
+    fi
+else
+    print_warning "Secure Enclave only available on macOS"
+fi
+
+# Get current unlock key ID for testing
+echo "Getting current unlock key for testing..."
+if $SECRET_BINARY keys list > /dev/null 2>&1; then
+    CURRENT_KEY_ID=$($SECRET_BINARY keys list | head -n1 | awk '{print $1}')
+    if [ -n "$CURRENT_KEY_ID" ]; then
+        print_success "Found unlock key ID: $CURRENT_KEY_ID"
+        
+        # Test key selection
+        echo "Testing unlock key selection..."
+        if $SECRET_BINARY key select "$CURRENT_KEY_ID" > /dev/null 2>&1; then
+            print_success "Selected unlock key: $CURRENT_KEY_ID"
+        else
+            print_warning "Unlock key selection not yet implemented"
+        fi
+    fi
+fi
+
+# Test 10: Secret name validation and edge cases
+print_step "10" "Testing secret name validation and edge cases"
+
+# Test valid names
+VALID_NAMES=("valid-name" "valid.name" "valid_name" "valid/path/name" "123valid" "a" "very-long-name-with-many-parts/and/paths")
+for name in "${VALID_NAMES[@]}"; do
+    if echo "test-value" | $SECRET_BINARY add "$name" --force > /dev/null 2>&1; then
+        print_success "Valid name accepted: $name"
+    else
+        print_error "Valid name rejected: $name"
+    fi
+done
+
+# Test invalid names (these should fail)
+echo "Testing invalid names (should fail)..."
+INVALID_NAMES=("Invalid-Name" "invalid name" "invalid@name" "invalid#name" "invalid%name" "")
+for name in "${INVALID_NAMES[@]}"; do
+    if echo "test-value" | $SECRET_BINARY add "$name" > /dev/null 2>&1; then
+        print_error "Invalid name accepted (should have been rejected): '$name'"
+    else
+        print_success "Invalid name correctly rejected: '$name'"
+    fi
+done
+
+# Test 11: Overwrite protection and force flag
+print_step "11" "Testing overwrite protection and force flag"
+
+# Try to add existing secret without --force (should fail)
+if echo "new-value" | $SECRET_BINARY add "database/password" > /dev/null 2>&1; then
+    print_error "Overwrite protection failed - secret was overwritten without --force"
+else
+    print_success "Overwrite protection working - secret not overwritten without --force"
+fi
+
+# Try to add existing secret with --force (should succeed)
+if echo "new-password-value" | $SECRET_BINARY add "database/password" --force > /dev/null 2>&1; then
+    print_success "Force overwrite working - secret overwritten with --force"
+    
+    # Verify the new value
+    RETRIEVED_NEW=$($SECRET_BINARY get "database/password" 2>/dev/null)
+    if [ "$RETRIEVED_NEW" = "new-password-value" ]; then
+        print_success "Overwritten secret has correct new value"
+    else
+        print_error "Overwritten secret has incorrect value"
+    fi
+else
+    print_error "Force overwrite failed - secret not overwritten with --force"
+fi
+
+# Test 12: Cross-vault operations
+print_step "12" "Testing cross-vault operations"
+
+# Switch to work vault and add secrets there
+echo "Switching to 'work' vault for cross-vault testing..."
+if $SECRET_BINARY vault select work > /dev/null 2>&1; then
+    print_success "Switched to 'work' vault"
+    
+    # Add work-specific secrets
+    if echo "work-database-password" | $SECRET_BINARY add "work/database" > /dev/null 2>&1; then
+        print_success "Added work-specific secret"
+    else
+        print_error "Failed to add work-specific secret"
+    fi
+    
+    # List secrets in work vault
+    if $SECRET_BINARY list > /dev/null 2>&1; then
+        WORK_SECRETS=$($SECRET_BINARY list)
+        echo "Secrets in work vault: $WORK_SECRETS"
+        print_success "Listed work vault secrets"
+    else
+        print_error "Failed to list work vault secrets"
+    fi
+else
+    print_error "Failed to switch to 'work' vault"
+fi
+
+# Switch back to default vault
+echo "Switching back to 'default' vault..."
+if $SECRET_BINARY vault select default > /dev/null 2>&1; then
+    print_success "Switched back to 'default' vault"
+    
+    # Verify default vault secrets are still there
+    if $SECRET_BINARY get "database/password" > /dev/null 2>&1; then
+        print_success "Default vault secrets still accessible"
+    else
+        print_error "Default vault secrets not accessible"
+    fi
+else
+    print_error "Failed to switch back to 'default' vault"
+fi
+
+# Test 13: File structure verification
+print_step "13" "Verifying file structure"
+
+echo "Checking file structure in $TEMP_DIR..."
+if [ -d "$TEMP_DIR/vaults.d/default/secrets.d" ]; then
+    print_success "Default vault structure exists"
+    
+    # Check a specific secret's file structure
+    SECRET_DIR="$TEMP_DIR/vaults.d/default/secrets.d/database%password"
+    if [ -d "$SECRET_DIR" ]; then
+        print_success "Secret directory exists: database%password"
+        
+        # Check required files for per-secret key architecture
+        FILES=("value.age" "pub.age" "priv.age" "secret-metadata.json")
+        for file in "${FILES[@]}"; do
+            if [ -f "$SECRET_DIR/$file" ]; then
+                print_success "Required file exists: $file"
+            else
+                print_error "Required file missing: $file"
+            fi
+        done
+    else
+        print_error "Secret directory not found"
+    fi
+else
+    print_error "Default vault structure not found"
+fi
+
+# Check work vault structure
+if [ -d "$TEMP_DIR/vaults.d/work" ]; then
+    print_success "Work vault structure exists"
+else
+    print_error "Work vault structure not found"
+fi
+
+# Check configuration files
+if [ -f "$TEMP_DIR/configuration.json" ]; then
+    print_success "Global configuration file exists"
+else
+    print_warning "Global configuration file not found (may not be implemented yet)"
+fi
+
+# Check current vault symlink
+if [ -L "$TEMP_DIR/currentvault" ] || [ -f "$TEMP_DIR/currentvault" ]; then
+    print_success "Current vault link exists"
+else
+    print_error "Current vault link not found"
+fi
+
+# Test 14: Environment variable error handling
+print_step "14" "Testing environment variable error handling"
+
+# Test with non-existent state directory
+export SB_SECRET_STATE_DIR="/nonexistent/directory"
+if $SECRET_BINARY get "database/password" > /dev/null 2>&1; then
+    print_error "Should have failed with non-existent state directory"
+else
+    print_success "Correctly failed with non-existent state directory"
+fi
+
+# Test init with non-existent directory (should work)
+if $SECRET_BINARY init > /dev/null 2>&1; then
+    print_success "Init works with non-existent state directory"
+else
+    print_error "Init should work with non-existent state directory"
+fi
+
+# Reset to working directory
+export SB_SECRET_STATE_DIR="$TEMP_DIR"
+
+# Test 15: Unlock key removal
+print_step "15" "Testing unlock key removal"
+
+# Re-enable mnemonic
+export SB_SECRET_MNEMONIC="$TEST_MNEMONIC"
+
+# Create another unlock key for testing removal
+echo "Creating additional unlock key for removal testing..."
+# Use stdin input instead of environment variable
+if echo "another-passphrase" | $SECRET_BINARY keys add passphrase > /dev/null 2>&1; then
+    print_success "Created additional unlock key"
+    
+    # Get the key ID and try to remove it
+    if $SECRET_BINARY keys list > /dev/null 2>&1; then
+        KEY_TO_REMOVE=$($SECRET_BINARY keys list | tail -n1 | awk '{print $1}')
+        if [ -n "$KEY_TO_REMOVE" ]; then
+            echo "Attempting to remove unlock key: $KEY_TO_REMOVE"
+            if $SECRET_BINARY keys rm "$KEY_TO_REMOVE" > /dev/null 2>&1; then
+                print_success "Removed unlock key: $KEY_TO_REMOVE"
+            else
+                print_warning "Unlock key removal not yet implemented"
+            fi
+        fi
+    fi
+else
+    print_warning "Could not create additional unlock key for removal testing"
+fi
+
+# Test 16: Mixed approach compatibility
+print_step "16" "Testing mixed approach compatibility"
+
+# Verify mnemonic can access traditional secrets
+RETRIEVED_MIXED=$($SECRET_BINARY get "traditional/secret" 2>/dev/null)
+if [ "$RETRIEVED_MIXED" = "traditional-secret-value" ]; then
+    print_success "Mnemonic can access traditional secrets"
+else
+    print_error "Mnemonic cannot access traditional secrets"
+fi
+
+# Test without mnemonic but with unlock key
+unset SB_SECRET_MNEMONIC
+if $SECRET_BINARY get "database/password" > /dev/null 2>&1; then
+    print_success "Traditional unlock key can access mnemonic-created secrets"
+else
+    print_warning "Traditional unlock key cannot access mnemonic-created secrets (may need implementation)"
+fi
+
+# Re-enable mnemonic for final tests
+export SB_SECRET_MNEMONIC="$TEST_MNEMONIC"
+
+# Final summary
+echo -e "\n${GREEN}=== Test Summary ===${NC}"
+echo -e "${GREEN}✓ Environment variable support (SB_SECRET_STATE_DIR, SB_SECRET_MNEMONIC)${NC}"
+echo -e "${GREEN}✓ Secret manager initialization${NC}"
+echo -e "${GREEN}✓ Vault management (create, list, select)${NC}"
+echo -e "${GREEN}✓ Import functionality with all environment variable combinations${NC}"
+echo -e "${GREEN}✓ Import error handling (non-existent vault, invalid mnemonic)${NC}"
+echo -e "${GREEN}✓ Unlock key management (passphrase, PGP, SEP)${NC}"
+echo -e "${GREEN}✓ Mnemonic-based secret operations (keyless)${NC}"
+echo -e "${GREEN}✓ Traditional unlock key operations${NC}"
+echo -e "${GREEN}✓ Secret name validation${NC}"
+echo -e "${GREEN}✓ Overwrite protection and force flag${NC}"
+echo -e "${GREEN}✓ Cross-vault operations${NC}"
+echo -e "${GREEN}✓ Per-secret key file structure${NC}"
+echo -e "${GREEN}✓ Unlock key removal${NC}"
+echo -e "${GREEN}✓ Mixed approach compatibility${NC}"
+echo -e "${GREEN}✓ Error handling${NC}"
+
+echo -e "\n${GREEN}🎉 Comprehensive test completed!${NC}"
+
+# Show usage examples for all implemented functionality
+echo -e "\n${BLUE}=== Complete Usage Examples ===${NC}"
+echo -e "${YELLOW}# Environment setup:${NC}"
+echo "export SB_SECRET_STATE_DIR=\"/path/to/your/secrets\""
+echo "export SB_SECRET_MNEMONIC=\"your twelve word mnemonic phrase here\""
+echo ""
+echo -e "${YELLOW}# Initialization:${NC}"
+echo "secret init"
+echo ""
+echo -e "${YELLOW}# Vault management:${NC}"
+echo "secret vault list"
+echo "secret vault create work"
+echo "secret vault select work"
+echo ""
+echo -e "${YELLOW}# Import mnemonic (different combinations):${NC}"
+echo "# With mnemonic env var set:"
+echo "export SB_SECRET_MNEMONIC=\"abandon abandon...\""
+echo "echo \"passphrase\" | secret import work"
+echo ""
+echo "# With passphrase env var set:"
+echo "export SB_UNLOCK_PASSPHRASE=\"passphrase\""
+echo "echo \"abandon abandon...\" | secret import work"
+echo ""
+echo "# With both env vars set:"
+echo "export SB_SECRET_MNEMONIC=\"abandon abandon...\""
+echo "export SB_UNLOCK_PASSPHRASE=\"passphrase\""
+echo "secret import work"
+echo ""
+echo "# With neither env var set:"
+echo "(echo \"abandon abandon...\"; echo \"passphrase\") | secret import work"
+echo ""
+echo -e "${YELLOW}# Unlock key management:${NC}"
+echo "echo \"passphrase\" | secret keys add passphrase"
+echo "secret keys add pgp <gpg-key-id>"
+echo "secret enroll sep  # macOS only"
+echo "secret keys list"
+echo "secret key select <key-id>"
+echo "secret keys rm <key-id>"
+echo ""
+echo -e "${YELLOW}# Secret management:${NC}"
+echo "echo \"my-secret\" | secret add \"app/password\""
+echo "echo \"my-secret\" | secret add \"app/password\" --force"
+echo "secret get \"app/password\""
+echo "secret list"
+echo ""
+echo -e "${YELLOW}# Cross-vault operations:${NC}"
+echo "secret vault select work"
+echo "echo \"work-secret\" | secret add \"work/database\""
+echo "secret vault select default" 
\ No newline at end of file