The difference between SSH1 and SSH2

// from the network
SSH (Secure SHell) So far there are two incompatible versions --SSH1 and SSH2.
ssh1 ssh2 protocols and ports are employed and Telnet is 22. 23. A
SSH1 divided into two versions 1.3 and 1.5. SSH1 using DES, 3DES, Blowfish symmetric encryption algorithm like RC4 and secure data transmission, the symmetric key encryption algorithm is accomplished by the exchange of asymmetric encryption algorithm (RSA). SSH1 using a cyclic redundancy check code (CRC) to ensure data integrity, but later found that this approach has drawbacks.
SSH2 RSA avoid the patent issues, and to repair defects in the CRC. SSH2 with Digital Signature Algorithm (DSA), and Diffie-Hellman (DH) algorithm in place to complete the exchange of symmetric RSA keys, confirmed with the message codes (HMAC) instead of CRC. At the same time increasing the AES and Twofish SSH2 other symmetric encryption algorithms.