PGCrypto with Integers and DATE types -- how to?

Hello,

How do you encrypt() & decrypt() data of types INT4 or DATE?

The PGCrypto methods encrypt() and decrypt() each take BYTEA as input:

i.e.,
encrypt( data::bytea, key::bytea, type::text)
decrypt( data::bytea, key::bytea, type::text)

So how do you convert INT4 and DATE data into BYTEA so that they can be
passed as input into the PGCrypto methods encrypt() & decrypt()?

Thank you,
Michael Moran