The remote Debian host is missing a security-related update.
Daniel Genkin, Lev Pachmanov, Itamar Pipman and Eran Tromer discovered that the ECDH secret decryption keys in applications using the libgcrypt11 library could be leaked via a side-channel attack. See https://www.cs.tau.ac.IL/~tromer/ecdh/ for details.
Upgrade the libgcrypt11 packages. For the oldstable distribution (wheezy), this problem has been fixed in version 1.5.0-5+deb7u4.