vankuik.nl: 2013-09-26 Speed comparison of different ciphers on an SSH tunnel

Today I got curious what the speed differences are when you use a different cipher for an SSH tunnel.

First, create a 100 MB testfile on the remote box:

 you@remote $ cd /var/www
 you@remote $ sudo dd if=/dev/urandom of=./testfile100mb.bin bs=1M count=100

Then set up a tunnel from your local desktop to your remote webserver, and use wget to test it:

In one terminal (using the default cipher here):

 you@local $ ssh -L8080:localhost:80 remote

In the other:

 you@local $ wget http://localhost:8080/testfile100mb.bin
 (3.87 MB/s) - ‘testfile100mb.bin’ saved

Now exit the tunnel and retry with another cipher:

 you@local $ ssh -c arcfour256 -L8080:localhost:80 remote

 you@local $ wget http://localhost:8080/testfile100mb.bin
 (3.87 MB/s) - ‘testfile100mb.bin.1’ saved

Hmmm, that's not much. And not encrypting anything doesn't work:

 you@local $ ssh -c none -L8080:localhost:80 remote
 No valid ciphers for protocol version 2 given, using defaults.