sftp/scp performance testing

[Dan Kaminsky]

> For curiosity's sake, how does sftp/scp performance compare when the
> underlying protocol is changed i.e rsa1 vs rsa2 vs dsa keys for
> encryption?

RSA1, RSA2, and DSA only affect session initialization -- they're basically
just the key exchange method used for the client and the server to sync up
to some random 3DES/AES/RC4 session key, which (someone verify this for me)
may or may not also be used for the SHA1/MD5 message authenticating layer as
well in the case of SSH2.

What should make a difference is whether the SSH1 or SSH2 protocols are
used -- SSH1 implicitly authenticates packets, for what cannot be decrypted
cannot be modified, while SSH2 uses a separate layer to guarantee that
packets are not modified in transit.

--Dan