sa3450 - Virtual Private Networking Concepts Guide

Cryptographic Systems and Encryption Terminology

2-10 Hewlett-Packard Company Virtual Private Networking Concepts Guide

Symmetric Vs. Asymmetric Cryptography

Symmetric Vs. Asymmetric CryptographySymmetric Vs. Asymmetric Cryptography

Symmetric Vs. Asymmetric Cryptography

Symmetric and asymmetric cryptography have some significant

differences. Symmetric cryptography tends to be fast compared

to asymmetric cryptography. Therefore, symmetric algorithms

are often used when large quantities of data need to be

exchanged and the 2 parties are known to each other.

Conversely, asymmetric algorithms are used when small

quantities of data need to be exchanged or the 2 parties are not

known to each other.

Asymmetric cryptography is often used during authentication

processes. Another significant difference between the 2 types of

cryptographic systems is the length of the keys required by the

algorithms. The keys used in symmetric algorithms are usually

much smaller than those used in asymmetric algorithms, as

described in the following table.

Related Related

Information

InformationInformation

Information

Asymmetric Cryptographic Systems (page 2-9)

Symmetric Cryptographic Systems (page 2-3)

Key Space and Brute Force Attacks (page 2-13)

Symmetric

SymmetricSymmetric

Symmetric Asymmetric

AsymmetricAsymmetric

Asymmetric

Speed Fast Slow

Key size Relatively small Extremely large

Key usage Shared secret Public/private

Usual usage Bulk data transfer Authentication

Examples DES, Triple Pass

DES, 3DES, rc4

RSA, PGP