Re: SCP file transfer speed

[Thor Lancelot Simon <tls%panix.com@localhost>]

On Fri, Mar 20, 2015 at 06:21:46AM +0000, Michael van Elst wrote:
> 
> You could try something like:
> 
> scp -oCiphers=arcfour ....
> 
> On a modern computer that's more than 4 times as fast as the default
> AES cipher. If you don't trust arcfour, maybe blowfish-cbc is good
> enough for you and still about 3 times as fast.

This strongly implies something's wrong with our libcrypto on "modern
computers".  On anything made in the last 3-4 years, AES should be
accellerated by hardware for userspace programs.

In fact it's so fast that it's more clear than ever the MAC is the
bottleneck.  For SSH sessions something like UMAC is almost certainly
appropriate (and supported by the client).

By all means, turn off compression.

Thor