If you want to store cc info encrypted, first encrypt the cc info, then store it in an entity field.
That's more efficient than using encryption on a db. Encryption on the DB level, thus encrypting and decrypting on the DB, isn't build in, you've to create that with DBFunctionCalls but it's cumbersome. What I'd do is encrypt/decrypt on the entity level, eventually adding a property in a partial class which encrypts/decrypts a value of an entity field using a certificate.