Speeding up Serpent: SIMD Edition
The Serpent block cipher was one of the 5 finalists in the AES competition, and is widely thought to be the most secure of them due to its conservative design. It was also considered the slowest candidate, which is one major reason it did not win the AES contest. However, it turns out that on modern machines one can use SIMD operations to implement Serpent at speeds quite close to AES.