I was using cipher rijndael-128 with 32 chars key. I also used EncryptableTrait, so some database columns were encrypted. But after update to PHP 7.1 it gives me error:

No supported encrypter found. The cipher and / or key length are invalid.

So I changed cypher from rijndael-128 to AES-256-CBC and everything works and I don't know why :-) I thought that all encrypted data in the database will be lost, because encryption cipher is different then cipher used before.

Anybody know how these ciphers works? Is there some kind of backward compatibility between Rijndael 128 and AES 256?

Thanks a lot!