Introduction to cryptography, Part 2, Symmetric cryptography
From the developerWorks archives
Date archived: May 14, 2019 | First published: March 01, 2001
Symmetric cryptography, otherwise known as secret key cryptography, has been in use for thousands of years in forms ranging from simple substitution ciphers to more complex constructions. However, developments in mathematics and the growth of computing power have made it possible to create ciphers that are effectively unbreakable. Symmetric systems are generally very fast but are vulnerable so that the key used to encrypt must be shared with whomever needs to decrypt the message. The IBM-developed cipher DES has been very widely used but is now at the end of its useful life and is due for replacement. Whatever cipher developers use in their applications, it's important to consider the methods used, to recognize the trade-offs that occur and to plan for a future with more powerful computer systems.
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