The remote host is missing an update to gnupg announced via advisory DSA 429-2.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%20429-2

Phong Nguyen identified a severe bug in the way GnuPG creates and uses ElGamal keys for signing. This is a significant security failure which can lead to a compromise of almost all ElGamal keys used for signing. The update provided in DSA 459-1 disables the use of this type of key, using an interim fix. This update, DSA 459-2, implements a more correct and permanent fix provided by David Shaw. For the current stable distribution (woody) this problem has been fixed in version 1.0.6-4woody3. We recommend that you update your gnupg package.