Managing Public Keys; Overview; Creating A Local Key Pair; Configuration Guidelines - HP FlexFabric 5930 Series Security Configuration Manual

Managing public keys

Overview

This chapter describes public key management for the asymmetric key algorithms including the
Revest-Shamir-Adleman Algorithm (RSA), the Digital Signature Algorithm (DSA), and the Elliptic Curve
Digital Signature Algorithm (ECDSA).
Many security applications, including SSH, SSL, and PKI, use asymmetric key algorithms to secure
communications between two parties, as shown in
separate keys (one public and one private) for encryption and decryption, in contrast to the symmetric
key algorithms, which use only one key.
Figure 15 Encryption and decryption
Sender
Plain text
A key owner can distribute the public key in plain text on the network but must keep the private key in
privacy. It is mathematically infeasible to calculate the private key even if an attacker knows the algorithm
and the public key.
The security applications use the asymmetric key algorithms for the following purposes:
Encryption and decryption—Any public key receiver can use the public key to encrypt information,
•
but only the private key owner can decrypt the information.
Digital signature—The key owner uses the private key to "sign" information to be sent, and the
•
receiver decrypts the information with the sender's public key to verify information authenticity.
RSA, DSA, and ECDSA can all perform digital signature, but only RSA can perform encryption and
decryption.
Asymmetric key algorithms enables secure key distribution on an insecure network, but the security
strength of an asymmetric key algorithm still depends on key size as with any symmetric key algorithm.

Creating a local key pair

Configuration guidelines

When you create a local key pair, follow these guidelines:
The key algorithm must be the same as required by the security application.
•
The key modulus length must be appropriate (see
•
higher the security, the longer the key generation time.
Key
Cipher text
Encryption
Figure 15. Asymmetric key algorithms use two
Key
Receiver
Plain text
Decryption
Table 5). The longer the key modulus length, the
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