diff --git a/browser/chromium/chromium_darwin.go b/browser/chromium/chromium_darwin.go
index 5028d99..af0b7b9 100644
--- a/browser/chromium/chromium_darwin.go
+++ b/browser/chromium/chromium_darwin.go
@@ -12,8 +12,8 @@ import (
 	"os/exec"
 	"strings"
 
+	"github.com/moond4rk/hackbrowserdata/crypto"
 	"github.com/moond4rk/hackbrowserdata/types"
-	"github.com/moond4rk/hackbrowserdata/utils/cryptoutil"
 )
 
 var (
@@ -49,7 +49,7 @@ func (c *Chromium) GetMasterKey() ([]byte, error) {
 	}
 	salt := []byte("saltysalt")
 	// @https://source.chromium.org/chromium/chromium/src/+/master:components/os_crypt/os_crypt_mac.mm;l=157
-	key := cryptoutil.PBKDF2Key(secret, salt, 1003, 16, sha1.New)
+	key := crypto.PBKDF2Key(secret, salt, 1003, 16, sha1.New)
 	if key == nil {
 		return nil, errWrongSecurityCommand
 	}
diff --git a/browser/chromium/chromium_linux.go b/browser/chromium/chromium_linux.go
index 8f14cb2..70034d8 100644
--- a/browser/chromium/chromium_linux.go
+++ b/browser/chromium/chromium_linux.go
@@ -11,8 +11,8 @@ import (
 	"github.com/godbus/dbus/v5"
 	keyring "github.com/ppacher/go-dbus-keyring"
 
+	"github.com/moond4rk/hackbrowserdata/crypto"
 	"github.com/moond4rk/hackbrowserdata/types"
-	"github.com/moond4rk/hackbrowserdata/utils/cryptoutil"
 )
 
 func (c *Chromium) GetMasterKey() ([]byte, error) {
@@ -69,7 +69,7 @@ func (c *Chromium) GetMasterKey() ([]byte, error) {
 	}
 	salt := []byte("saltysalt")
 	// @https://source.chromium.org/chromium/chromium/src/+/master:components/os_crypt/os_crypt_linux.cc
-	key := cryptoutil.PBKDF2Key(secret, salt, 1, 16, sha1.New)
+	key := crypto.PBKDF2Key(secret, salt, 1, 16, sha1.New)
 	c.masterKey = key
 	slog.Info("get master key success", "browser", c.name)
 	return key, nil
diff --git a/crypto/asn1pbe.go b/crypto/asn1pbe.go
index 73c2a22..4c2b97c 100644
--- a/crypto/asn1pbe.go
+++ b/crypto/asn1pbe.go
@@ -6,8 +6,6 @@ import (
 	"crypto/sha256"
 	"encoding/asn1"
 	"errors"
-
-	"github.com/moond4rk/hackbrowserdata/utils/cryptoutil"
 )
 
 type ASN1PBE interface {
@@ -158,7 +156,7 @@ func (m metaPBE) deriveKeyAndIV(globalSalt []byte) ([]byte, []byte) {
 	iter := m.AlgoAttr.Data.Data.SlatAttr.IterationCount
 	keyLen := m.AlgoAttr.Data.Data.SlatAttr.KeySize
 
-	key := cryptoutil.PBKDF2Key(password[:], salt, iter, keyLen, sha256.New)
+	key := PBKDF2Key(password[:], salt, iter, keyLen, sha256.New)
 	iv := append([]byte{4, 14}, m.AlgoAttr.Data.IVData.IV...)
 	return key, iv
 }
diff --git a/utils/cryptoutil/cryptoutil.go b/crypto/pbkdf2.go
similarity index 98%
rename from utils/cryptoutil/cryptoutil.go
rename to crypto/pbkdf2.go
index 6838ecf..2e016df 100644
--- a/utils/cryptoutil/cryptoutil.go
+++ b/crypto/pbkdf2.go
@@ -1,4 +1,4 @@
-package cryptoutil
+package crypto
 
 import (
 	"crypto/hmac"