Access Restriction

Author Merkle, Ralph C. ♦ Hellman, Martin E.
Source ACM Digital Library
Content type Text
Publisher Association for Computing Machinery (ACM)
File Format PDF
Language English
Subject Keyword Des ♦ Data encryption standard ♦ Cryptanalysis ♦ Cipher ♦ Encryption ♦ Cryptography ♦ Multiple encryption ♦ Encipher ♦ Encrypt
Abstract Double encryption has been suggested to strengthen the Federal Data Encryption Standard (DES). A recent proposal suggests that using two 56-bit keys but enciphering 3 times (encrypt with a first key, decrypt with a second key, then encrypt with the first key again) increases security over simple double encryption. This paper shows that although either technique significantly improves security over single encryption, the new technique does not significantly increase security over simple double encryption. Cryptanalysis of the 112-bit key requires about 256 operations and words of memory, using a chosen plaintext attack. While DES is used as an example, the technique is applicable to any similar cipher.
Description Affiliation: Elxsi, Int., Sunnyvale, CA (Merkle, Ralph C.) || Stanford Univ., Stanford, CA (Hellman, Martin E.)
Age Range 18 to 22 years ♦ above 22 year
Educational Use Research
Education Level UG and PG
Learning Resource Type Article
Publisher Date 2005-08-01
Publisher Place New York
Journal Communications of the ACM (CACM)
Volume Number 24
Issue Number 7
Page Count 3
Starting Page 465
Ending Page 467

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Source: ACM Digital Library