This is from man ssh: I cant remember, but isnt it either a 128
bit or a 512 bit alphanumeric key? ssh supports RSA based
authentication. The scheme is based on public-key cryptography:
there are cryptosystems where encryption and decryption are done
using separate keys, and it is not possible to derive the
decryption key from the encryption key. RSA is one such system.
The idea is that each user creates a public/private key pair for
authentication purposes. The server knows the public key, and
only the user knows the private key. The file
$HOME/.ssh/authorized_keys lists the public keys that are
permitted for logging in. When the user logs in, the ssh program
tells the server which key pair it would like to use for
authentication. The server checks if this key is permitted, and
if so, sends the user (actually the ssh program running on
behalf of the user) a challenge, a random number, encrypted by
the user's public key. The challenge can only be decrypted using
the proper private key. The user's client then