encrypted string always the same

[Marius Andreiana]

Hi

I saw everytime a text is encrypted with the same public key, the result
is different.
I'm trying to store gpg-encrypted values in a database, but would like
to be able to tell if a user-entered value matches the encrypted one in
database (by crypting it with the same public key).
Is it possible? Any options I could pass to gpg so it always encrypts
with the same result? 

I realize this makes it vulnerable to brute-force attack (I encrypt
short 4-digit strings and other short stuff).

Thanks!

-- 
Marius Andreiana
Galuna - Solutii Linux in Romania
http://www.galuna.ro