RC4 (arcfour) should not be used, because it's broken. It has biases in its output (which is XOR-ed with the plaintext), which given enough cyphertext allows on

RC4 (arcfour) should not be used, because it's broken. It has biases in its output (which is XOR-ed with the plaintext), which given enough cyphertext allows one to recover the plaintext (see http://www.rc4nomore.com/ http://www.rc4nomore.com/ for the most recent result). OpenSSH since the 6.5 release (http://www.openssh.com/txt/release-6.5 http://www.openssh.com/txt/release-6.5) has a better alternative, ChaCha20. It's even faster than RC4, and has no known weaknesses AFAIK. Some more information: https://security.stackexchange.com/questions/46812/what-does-chacha20-poly1305openssh-com-mean-for-me https://security.stackexchange.com/questions/46812/what-does...