There is abundant literature on the security of Data Encryption Standard (DES or 3DES). Today we have released a new way to attack this cipher, see Section 11 in here. Anyone who reads this paper should immediately see that the high confidence which have developed over decades in research community about our ability to design secure block ciphers was never justified in any way and an incredibly rich space of attacks with unique powerful features is now available to study.
Added Jun. 2019: here are slides presented at CECC 2019 (invited talk).
Added Oct. 2019: here are slides presented at the 2019 Symposium on Cryptologic History, 17-19 October 2019, Kossiakoff Centre, Laurel, MD, USA. Here is the program.
Added December 2019: Here are the slides presented at ICISC conference in Seoul Korea, “Systematic Construction of Nonlinear Product Attacks on Block Ciphers”, on 4 December 2019.