The same key is used for both encryption and decryption. Supported symmetric key algorithms include
DES, 3DES, and AES, which can effectively prevent data eavesdropping.
z
Asymmetric key algorithm
Asymmetric key algorithm is also called public key algorithm. Both ends have their own key pair,
consisting of a private key and a public key. The private key is kept secret while the public key may be
rivate key can be decrypted only with the corresponding private
use the asymmetric key algorithm for data signature. For example, user 1 adds his
oth Revest-Shamir-Adleman Algorithm (RSA) and Digital Signature Algorithm (DSA) are asymmetric
ms. RSA is used for data encryption and signature, whereas DSA is used for adding
rrently the switch supports only RSA .
distributed widely. The private key cannot be practically derived from the public key. The information
encrypted with the public key/p
key/public key.
Asymmetric key algorithm encrypts data using the public key and decrypts the data using the private
key, thus ensuring data security.
You can also
signature to the data using the private key, and then sends the data to user 2. User 2 verifies the
signature using the public key of user 1. If the signature is correct, this means that the data originates
from user 1.
B
key algorith
signature. Cu
Symmetric key algorithms are used for encryption and decryption of the data transferred on the SSH
c key algorithms are used for digital signature and identity authentication.
channel while asymmetri
SSH Operating Process
The session e
ent between an SSH client and the SSH server involves the following five
stages:
Table 55
stablishing a ses
e SSH client and server
stablishm
-1
Stages in e
sion between th
Stages
Description
Version negotiation
SSH1 and SSH2 are supported. The two parties negotiate a
version to use.
Key and algorithm negotiation
gotiate
SSH supports multiple algorithms. The two parties ne
an algorithm for communication.
Authentication
The SSH server authenticates the client in response to the
client’s
authentication request.
Session request
This client sends a session request to the server.
The client and the server start to communicate with each
other.
Data exchange
