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);
    }

    /**

>> 31) } // ConstantTimeEq returns 1 if x == y and 0 otherwise. func ConstantTimeEq(x, y int32) int { return int((uint64(uint32(x^y)) - 1) >> 63) } // ConstantTimeCopy copies the contents of y into x (a slice of equal length) // if v == 1. If v == 0, x is left unchanged. Its behavior is undefined if v // takes any other value. func ConstantTimeCopy(v int, x, y []byte) { if len(x) != len(y) { panic("subtle: slices have different lengths") } xmask := byte(v - 1) ymask := byte(^(v - 1)) for i := 0; i...