How does the SSH protocol work?

by Amrita Mitra | Mar 5, 2017 | CCNA, CCNP, CompTIA, Data Breaches and Prevention, Encryption, Security Fundamentals

communication, the client again sends the key ID to the server after the symmetric key is established successfully between them. The server checks the key ID and tries to find a corresponding match of the public key from the stored public keys. If a match is found, then the server generates a random number and sends the random number encrypted with the public key of the client. The client will possess its corresponding private key. So, it will decrypt the random number and then send an MD5 hash of the random number after encrypting it with the session key.

The server now calculates the MD5 hash of the random number it sent and verifies it with the bytes it got from the client after decrypting it with the session key. If both the values match, the authenticity of the client is successful. Now, the server and the client can communicate with each other securely, and the data can be encrypted with the session key established between them previously.

So, this is how SSH works. I hope this helps.

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