KNOT is a family of bit-slice lightweight AEAD (Authenticated Encryption with Associated Data) and hashing algorithms. It is currently one of the Round 2 candidates in the NIST lightweight cryptography standardization process.

Owing to the bit-slice style, KNOT allows for very efficient and flexible implementations in both hardware and software environments. Due to its Duplex/Sponge modes, compact state size, 4-bit Sbox and a bit permutation based diffusion layer, KNOT is well-suited for different constrained devices. Moreover, the implementation of the round function can be reused in the KNOT-AEAD and KNOT-Hash of the same KNOT-Pair, which reduces the hardware area or software ROM. The bit-slice style, together with carefully selected S-box, enables efficient side-channel resistant implementations of KNOT.

Resources:

1. Specification and Supporting Document 

2. Reference code in C

3. Hardware implementations

We have delivered our hardware implementations of KNOT to the Athena project for further benchmarking.

4. Microcontroller implementations

We have delivered several microcontroller implementations to the OTH Regensburg initiative for further benchmarking.

Authors:

Wentao Zhang           Institute of Information Engineering, CAS           zhangwentao@iie.ac.cn

Tianyou Ding            Institute of Information Engineering, CAS           dingtianyou@iie.ac.cn

Bohan Yang              Tsinghua University                                                 bohanyang@tsinghua.edu.cn

Zhenzhen Bao           Nanyang Technological University                        baozhenzhen10@gmail.com

Zejun Xiang              Hubei University                                                      xiangzejun@hubu.edu.cn

Fulei Ji                      Institute of Information Engineering, CAS            jifulei@iie.ac.cn

Xuefeng Zhao           Institute of Information Engineering, CAS            zhaoxuefeng@iie.ac.cn

Chunning Zhou        Institute of Information Engineering, CAS            zhouchunning@iie.ac.cn

Related Links:

1. NIST Lightweight Cryptography project

2. Athena project

3. eBACS: ECRYPT Benchmarking of Cryptographic Systems

4. OTH Regensburg initiative

5. SW benchmarking by Rhys Weatherly