Ahem.. Something went wrong, so here it is again AYIYA tunnels sign every packet with a sha1 hash. VIA C5, C7 and nano processors have built in hardware acceleration for sha1 hashes. So I developed a patch for AICCU that will do this. Note that this patch only works on the unix source, and a gcc compiler. It only accelerates AYIYA tunnels, not heartbeat and static tunnels. On my machine the hash algorithm is up to 4 times faster than the current one. Get the patch here: http://home.student.utwente.nl/n.werensteijn/aiccu_padlock.patch.bz2 Instructions: 1. Download and unpack AICCU source. 2. Apply patch: (bzcat aiccu_padlock.patch.bz2 | patch -p0) 3. Make using PADLOCK=enabled cd aiccu make PADLOCK=enabled aiccu 4. Install sudo make install Enjoy. Let me know if you run into problems.