CLOC and SILC---Authenticated Encryption Schemes for Constrained Devices


An authenticated encryption scheme (AE) is a symmetric-key cryptographic function for both confidentiality and integrity. CLOC and SILC are blockcipher modes for AE designed in 2014, where CLOC stands for Compact Low-Overhead CFB and SILC for SImple Lightweight CFB. The main target of these modes is constrained devices having limited resources for computation and memory, which will play the key role in the forthcoming era of Internet of Things (IoT). CLOC and SILC are designed to minimize the memory and computation overhead beyond the underlying blockcipher, and they show good performance for short input data. The primary focus of CLOC is embedded software, such as low-end 8-bit micro-controllers, and the focus of SILC is small hardware, such as RFID or ASIC, or programmable logic device, e.g. CPLD.

CLOC and SILC are candidates of CAESAR, a cryptographic competition of AE organized by leading cryptographers.

CLOC was first presented at FSE 2014, and SILC was first presented at DIAC 2014.


Tetsu Iwata (Nagoya University, Japan)
Kazuhiko Minematsu (NEC Corporation, Japan)
Jian Guo (Nanyang Technological University, Singapore)
Sumio Morioka (NEC Europe, United Kingdom)

CLOC designers, and Eita Kobayashi (NEC Corporation, Japan)


Talks and slides



iwata (at) cse (dot) nagoya-u (dot) ac (dot) jp

Last update: July 21, 2017.