Editing Lucifer (cipher) (section)

{{short description|Earliest civilian block ciphers}}
{{Infobox block cipher
| name          = Lucifer
| image         = 
| caption       = 
| designers     = [[Horst Feistel]] et al.
| publish date  = 1971
| derived from  = 
| derived to    = [[Data Encryption Standard|DES]]
| related to    =
| certification = 
| key size      = 48, 64 or 128 bits
| block size    = 48, 32 or 128 bits
| structure     = [[Substitution–permutation network]], [[Feistel network]]
| rounds        = 16
| cryptanalysis = 
}}
In [[cryptography]], '''Lucifer''' was the name given to several of the earliest civilian [[block cipher]]s, developed by [[Horst Feistel]] and his colleagues at [[IBM]].  Lucifer was a direct precursor to the [[Data Encryption Standard]].  One version, alternatively named '''DTD-1''',<ref>{{Cite web|title=QDLPluginEncryptionPS Reference - QDLPlgLucifer|url=http://www.patisoftware.eu/developCentral/QDLPlgPSLibRoot/UserReferences/QDLPluginEncryptionPS_UserRef/QDLPlgLucifer.html|access-date=2020-11-22|website=www.patisoftware.eu}}</ref> saw commercial use in the 1970s for electronic [[banking]].