00339nam a22001337a 4500020001800000100001800018245002700036260004000063300001300103490004100116650001300157650001800170650001700188  a9789349750197  aKnospe, Heiko  aCourse in cryptography  aTelanganabUniversities pressc2019  axvii+323  aPure and applied undergraduate texts  aSageMath  aNumber theory  aBlock cipher