Article · Wikipedia archive · Last revised May 28, 2026

Null encryption

In modern cryptography, null encryption is choosing not to use encryption in a system where various encryption options are offered. When this option is used, the text is the same before and after encryption, which can be practical for testing/debugging, or authentication-only communication. In mathematics such a function is known as the identity function.

Last revised
May 28, 2026
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In modern cryptography, null encryption (or selecting null cipher or NONE cipher) is choosing not to use encryption in a system where various encryption options are offered. When this option is used, the text is the same before and after encryption, which can be practical for testing/debugging, or authentication-only communication. In mathematics such a function is known as the identity function.

Examples of this are the "eNULL" cipher suite in OpenSSL,1 and the "NULL Encryption Algorithm" in IPSec.2

See also

See also

  • RFC 2410: "The NULL Encryption Algorithm and Its Use With IPsec"
References

References

  1. "ciphers - SSL cipher display and cipher list tool". OpenSSL. Retrieved 2014-12-10.
  2. RFC 2410 - The NULL Encryption Algorithm and Its Use With IPsec