HC-128
A 2004 stream cipher with a 128-bit key, written for software and driven by large tables in memory rather than shift registers.
HC-128 was presented in 2004 by Hongjun Wu as part of the eSTREAM project. It uses large tables in memory that are updated while the cipher runs, instead of linear feedback shift registers. That was a deliberate choice: LFSR-based designs had shown weaknesses, so HC-128 went another way.
HC-128 made it into the eSTREAM software portfolio in 2008. It shows how cryptographers sometimes build designs that are fast on a computer but hard to implement safely, and how table-driven ciphers demand care against side-channel leaks.