I posted this question in alt.security.pgp, but got no response so I'm
trying here.

I have a situation where there will be multiple people encrypting
documents that my application will need to decrypt. They will encrypt
with a common public key that all will use and sign with their own
private key, unique to each individual.

Currently, the app decrypts fine using the common private key and one
of the users public keys. Now I need to decrypt documents encrypted
with 1 of 3 private keys. I'm not sure how to check additional private
keys. It looks like the method getVerificationKey( ) in the class
StreamDecryptVerify could help, but I'm not certain how to implement
it to use multiple private keys.

Anyone who has a suggestion, it would be appreciated.