Web Server Encrypt

[Nathan Heagy]

I'm setting up a cgi to encrypt files for a specific user. I've given the
web server a minimal gnupg installation - it only has the public key
required to encrypt the files. The problem is that gpg insists on asking
"Use this key anyway?". I do not want the web server to have a key pair of
its own. Is there any way to tell gpg to use this key without prompting
me? Even setting trust level to 4 hasn't helped.

thanks,

Nathan