PC1 cipher

The PC1 cipher, also called the Kindle cipher or Pukall cipher 1, is a block cipher introduced in 1991. It is most prominently used by Amazon, Inc., for their Kindle e-book reader's DRM system.

History

The PC1 cipher was designed by Alexander Pukall in 1991.

Successors

Caracachs Cipher formerly known as PC3 Cipher was released in 2000. This algorithm was used by the North Korean hacker group Lazarus Group.
PC4 was released in 2015. It's a block cipher specifically designed for DMR radio communication systems. It uses 253 rounds and the key size can vary from 8 bits to 2112 bits. The block size is 49 bits, the exact size of an AMBE+ DMR voiceframe.