> NSA worked closely with IBM to strengthen the algorithm against all except brute-force attacks and to strengthen substitution tables, called S-boxes. Converse

> NSA worked closely with IBM to strengthen the algorithm against all except brute-force attacks and to strengthen substitution tables, called S-boxes. Conversely, NSA tried to convince IBM to reduce the length of the key from 64 to 48 bits. Ultimately they compromised on a 56-bit key.[13][14] From wikipedia. Major compromise tbh :unamused: [13] Thomas R. Johnson (2009-12-18). "American Cryptology during the Cold War, 1945-1989.Book III: Retrenchment and Reform, 1972-1980, page 232" (PDF). National Security Agency. Archived (PDF) from the original on 2015-04-25. Retrieved 2015-07-16 – via National Security Archive FOIA request. This version is differently redacted than the version on the NSA website. [14] Thomas R. Johnson (2009-12-18). "American Cryptology during the Cold War, 1945-1989.Book III: Retrenchment and Reform, 1972-1980, page 232" (PDF). National Security Agency. Archived (PDF) from the original on 2015-04-25. Retrieved 2015-07-16 – via National Security Archive FOIA request. This version is differently redacted than the version on the NSA website.