final byte[] ciphertext = new byte[encrypted.length - tagLength];
        final byte[] authTag = new byte[tagLength];

        // Use constant-time copy operations
        constantTimeCopy(encrypted, 0, ciphertext, 0, ciphertext.length);
        constantTimeCopy(encrypted, ciphertext.length, authTag, 0, tagLength);

        return new EncryptionResult(ciphertext, authTag);
    }

    /**