This encryption add-on was was published years ago as a GitHub gist, but might be a nice starting point if you need encrypted data storage. The add-on encrypts all Gravity Forms data on the way into the database using openssl public encryption. Data can only be decrypted with the associated private key.



Gravity Extend also lists Encrypted Fields, which will get you on track much faster. Additionally there is the PGP Encryption Mail add-on, for PGP Encrypted e-mail notifications.