Question

Discuss the history of encryption from DES through AES

Answer 1

"History of Encryption: Threats to computer and network security increases with each passing day. No computer (or) network is immune from attacks Encryption or ability to store and transmit information in form that is unreadable to anyone other than intended persons, is critical element of our defence attacks * Indeed man has spend thousands of years in the quest for strong encryption algorithms DES: DES was based on algorithm developed by IBM and modified by National security Agency(NSA) .DES was considered unbreakable in 1970's except by brute force attack - that is trying every possible key (DES uses a 56 - bit key, so there are 2^56 (on 72, 057, 594, 037, 927, 936 of them) .By late 1990's however it was possible to break DES in matter of several days .This was possible because of relatively small block size (64bits) and key size advances in \r\n Computing power according to Moore's Law AES: In January 1997, NIST announced a competition for successor to DES . TO allay the suspicions that NSA had placed ""black doors"" in DES, the competition was to be open and public, and encryption algorithm was available for free worldwide . This critia included not only cryptographic strength but also case of implementation and performance in software and hardware."