Secure communication via symmetric algorithms
Secure communication via symmetric algorithms
Hello everyone. Please consider this a query about SSH symmetric encryption. The main idea is that symmetric keys encrypt all communication during an SSH session. Both the client and server generate the secret key together using a shared method, and neither party ever reveals the key to anyone else. This key generation happens through a key exchange algorithm. What makes it secure is that the key never travels between the client and the server—it’s exchanged via public data, which both computers share and use to compute the key independently. Even if someone intercepts this shared information, they can’t derive the key because the algorithm remains secret.
The statement clarifies that if a sniffer captures the public data, it could still reconstruct the key since the algorithm isn’t exposed. Encryption keys are set before any connection, and the same applies to the key exchange process. Communication happens over a simple medium like the internet, so the agreement on encryption methods is also sent through that channel. Even before a connection is made, both sides attempt to agree on the key exchange method.
So, if I understand correctly, a sniffer with access to public data and the encryption method could potentially create the symmetric key and decrypt intercepted packets. Is this accurate? Thank you!
In theory, it seems possible, though there might be measures in place to stop it, such as altering the algorithm once the connection is set up—using one for connection and another for sending data. But I’m not an expert.