The FSE Test of Time Award is given yearly. An award will be given in year X to honor a paper published at FSE/ToSC in year X-15 which has had a lasting impact on the field.
More information about the Test of Time award can be found in the policy guidelines document.
New Blockcipher Modes of Operation with Beyond the Birthday Bound Security
The 128-bit Blockcipher CLEFIA
Taizo Shirai, Kyoji Shibutani, Toru Akishita, Shiho Moriai, and Tetsu Iwata
A Meet-in-the-Middle Attack on 8-Round AES
Huseyin Demirci and Ali Aydin Selçuk