Configuring Ciphers

The algorithm(s) used for session encryption can be specified in the sshd2_config file:

Ciphers             aes128-cbc,3des-cbc

The system will attempt to use the different encryption ciphers in the sequence specified on the line. Currently supported cipher names are the following:

`aes128-cbc`	`blowfish-cbc`	`twofish256-cbc`
`aes192-cbc`	`cast128-cbc`	`cast128-12-cbc@ssh.com`
`aes256-cbc`	`twofish-cbc`	`des-cbc@ssh.com`
`3des-cbc`	`twofish128-cbc`	`seed-cbc@ssh.com`
`arcfour`	`twofish192-cbc`	`rijndael-cbc@ssh.com`

Special values for this option are the following:

Any: allows all the ciphers including none
AnyStd: allows only the ciphers mentioned in IETF SecSh draft and none. The standard ciphers are aes128-cbc, 3des-cbc, twofish128-cbc, cast128-cbc, twofish-cbc, blowfish-cbc, idea-cbc, aes192-cbc, aes256-cbc, twofish192-cbc, twofish256-cbc, and arcfour.
none: no encryption, connection will be in plaintext
AnyCipher: allows any available cipher apart from the non-encrypting cipher mode none
AnyStdCipher: the same as AnyCipher, but includes only those ciphers mentioned in IETF SecSh draft (excluding none)

The default ciphers are aes128-cbc, aes192-cbc, aes256-cbc and 3des-cbc.