just encrypt it with symmetric cipher in ECB mode of operation.
For 128-bit GUID use AES-128 is perfect. You can still compare if the two GUIDs are the same without decrypting, but you need to decrypt to get the real GUID.
For 128-bit GUID use AES-128 is perfect. You can still compare if the two GUIDs are the same without decrypting, but you need to decrypt to get the real GUID.