diff --git a/app/src/main/java/com/rosetta/messenger/crypto/MessageCrypto.kt b/app/src/main/java/com/rosetta/messenger/crypto/MessageCrypto.kt
index 2a95349..814efe7 100644
--- a/app/src/main/java/com/rosetta/messenger/crypto/MessageCrypto.kt
+++ b/app/src/main/java/com/rosetta/messenger/crypto/MessageCrypto.kt
@@ -736,8 +736,9 @@ object MessageCrypto {
             // which replaces invalid UTF-8 sequences with U+FFFD
             val password = bytesToJsUtf8String(plainKeyAndNonce)
             
-            // Compress with pako (deflate)
-            val deflater = java.util.zip.Deflater()
+            // Compress with raw deflate (NO zlib header) - matching pako.deflate()
+            // CRITICAL: nowrap=true for raw deflate (pako default)
+            val deflater = java.util.zip.Deflater(java.util.zip.Deflater.DEFAULT_COMPRESSION, true)
             deflater.setInput(replyJson.toByteArray(Charsets.UTF_8))
             deflater.finish()
             val compressedBuffer = ByteArray(replyJson.length * 2 + 100)
@@ -745,17 +746,10 @@ object MessageCrypto {
             deflater.end()
             val compressed = compressedBuffer.copyOf(compressedSize)
             
-            // PBKDF2 key derivation (matching RN: crypto.PBKDF2(password, 'rosetta', {keySize: 256/32, iterations: 1000}))
-            // CRITICAL: Must use SHA256 to match React Native (not SHA1!)
-            val factory = javax.crypto.SecretKeyFactory.getInstance("PBKDF2WithHmacSHA256")
-            val spec = javax.crypto.spec.PBEKeySpec(
-                password.toCharArray(),
-                "rosetta".toByteArray(Charsets.UTF_8),
-                1000,
-                256
-            )
-            val secretKey = factory.generateSecret(spec)
-            val keyBytes = secretKey.encoded
+            // PBKDF2 key derivation (matching crypto-js)
+            // CRITICAL: Use our custom implementation that properly handles UTF-8!
+            // Java's PBEKeySpec uses UTF-16, but crypto-js uses UTF-8
+            val keyBytes = generatePBKDF2Key(password)
             
             // Generate random IV (16 bytes)
             val iv = ByteArray(16)