phpseclib: pure PHP implementations of SSH, SFTP, RSA and X.509Compatibility phpseclib is designed to be ultra-compatible. It works on PHP4+ (PHP4, assuming the use of PHP_Compat) and doesn't require any extensions. For purposes of speed, mcrypt is used if it's available as is gmp or bcmath (in that order), but they are not required. Interoperability phpseclib is designed to be fully interoperable with OpenSSL and other standardized cryptography programs and
