Einführung in die Kryptographie (141022-WiSe19/20)

Goals

The stu­dents un­der­stand es­sen­ti­al sym­me­tric en­cryp­ti­on sys­tems in prac­tice and the ba­sics of asym­me­tric cryp­to­gra­phy. Fur­ther­mo­re, the stu­dents fa­mi­li­a­ri­ze them­sel­ves with the ways of thin­king in mo­dern cryp­to­gra­phy.

Con­tent

In the be­gin­ning, the fun­da­men­tal con­cepts of cryp­to­gra­phy and in­for­ma­ti­on se­cu­ri­ty are in­tro­du­ced, as well as some his­to­ri­cal ciph­ers. Next, stream ciph­ers are in­tro­du­ced. The main part of the lec­tu­re con­cerns block ciph­ers and their ap­p­li­ca­ti­ons. As im­portant ex­am­ples of sym­me­tric cryp­to­gra­phic sys­tems, the Data En­cryp­ti­on Stan­dard (DES) and Ad­van­ced En­cryp­ti­on Stan­dard (AES) are in­tro­du­ced. As the last part of the lec­tu­re, the prin­ci­ples of asym­me­tric cryp­to­gra­phy are in­tro­du­ced, in par­ti­cu­lar the wi­de­ly-used RSA crypto­sys­tem.

In ad­di­ti­on to cryp­to­gra­phic al­go­rith­ms, the ma­the­ma­ti­cal con­cepts that are nee­ded for the al­go­rith­ms are in­tro­du­ced, e.g., mo­du­lar arith­me­tic, the Eu­cli­di­an al­go­rithm and fi­ni­te fields.