Encyclopedia of Database Systems

2018 Edition
| Editors: Ling Liu, M. Tamer Özsu

Symmetric Encryption

  • Ninghui LiEmail author
Reference work entry
DOI: https://doi.org/10.1007/978-1-4614-8265-9_1484


Secret-key encryption


Symmetric encryption, also known as secret key encryption, is a form of data encryption where a single secret key is used for both encryption and decryption.

Key Points

Modern symmetric encryption algorithms are often classified into stream ciphers and block ciphers. In a stream cipher, the key is used to generate a pseudo-random key stream, and the ciphertext is computed by using a simple operation (e.g., bit XOR or modular addition) to combine the plaintext bits and the key stream bits. Many stream ciphers implemented in hardware are constructed using linear feedback shift registers (LFSRs). The use of LFSRs on their own, however, is insufficient to provide good security. Additional variation and enhancement are needed to increase the security of LFSRs. RC4 is the most widely-used software stream cipher and is used in popular protocols such as Secure Sockets Layer (SSL) (to protect Internet traffic) and WEP (to secure wireless networks).


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Recommended Reading

  1. 1.
    Federal information processing standards publication 46–3: data encryption standard (DES), 1999.Google Scholar
  2. 2.
    Federal information processing standards publication 197: advanced encryption standard, November 2001.Google Scholar

Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Purdue UniversityWest LafayetteUSA

Section editors and affiliations

  • Elena Ferrari
    • 1
  1. 1.DiSTAUniv. of InsubriaVareseItaly