Huawei Certified ICT Expert – Routing and Switching (HCIE-RS) — Question 4

In the SSH algorithm negotiation phase, the SSH server and client exchange the list of algorithms that hey support. The list of symmetric encryption algorithms of the SSH server is as follows: aes256-ctr, aes192-ctr, aes128-ctr, and aes256-cbc. The list of symmetric encryption algorithms of the SSH client is as follows: aes128-ctr, aes192-ctr, aes256-ctr, and aes256-cbc. Which of the following symmetric encryption algorithms can be used by both the SSH server and client?

Answer options

Correct answer: C

Explanation

The correct answer is aes128-ctr, as it is the only symmetric encryption algorithm that appears in both the SSH server and client lists. The other options, aes256-ctr, aes192-ctr, and aes256-cbc, are not supported by both parties simultaneously.