DES 1983, no problem. First publicly available algorithm certified by Nsa as secure. Certificate to be renewed every 5 years 1987, passed, but NSa says that des soon will be vulnerable to brute force attack. This is the last time Business lobbies to keep it, since so the had much invested 1993, still passed(no alternatives) 1997, call for proposals: AES3 DES • 1983, no problem. First publicly available algorithm certified by NSA as secure. Certificate to be renewed every 5 years. • 1987, passed, but – NSA says that DES soon will be vulnerable to brute￾force attack. This is the last time. – Business lobbies to keep it, since so the had much invested. • 1993, still passed (no alternatives). • 1997, call for proposals: AES