Passwords and Authentication - Passwords and Authentication Well who are you(Who are you Who who who who I really wanna know(Who are you Who who who who

Passwords and Authentication - Passwords and Authentication...

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Well, who are you? (Who are you? Who, who, who, who?)
Encrypted passwords4Trusted subsystem comparesto stored valueTerminalLogin sends<“obama”, DES(0, “hoopsguy”)>Trusted subsystemLogin:obamaPassword: hoopsguy
Encrypted passwords4Trusted subsystem comparesto stored valueTerminalLogin sends<“obama”, DES(0, “hoopsguy”)>Problem: anyone could simplylook up DES(0, “hoopsguy”)in the password fileand send that value…Trusted subsystemLogin:obamaPassword: hoopsguy
Encrypted passwords redux5TerminalTrusted subsystem
Encrypted passwords redux5TerminalLogin sends<“obama”, “hoopsguy”>Trusted subsystemLogin:obamaPassword: hoopsguy
Encrypted passwords redux5Trusted subsystem compares DES(0,“hoopsguy”) to password fileTerminalLogin sends<“obama”, “hoopsguy”>Trusted subsystemLogin:obamaPassword: hoopsguy
Use a slower encryption algorithmDES is pretty slowLimits the speed with which attackers can compute strings from passwordsEven slower: run DES many timesUnix uses DES25(0, password)Not more secure, but a lot slower…Require longer passwordsDES key is only 56 bits long, so it only uses the first 7.5 ASCII characters of the password: problem!

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