TiGER: Tiny bandwidth key encapsulation mechanism for easy miGration based on RLWE(R)

This project contains the implementation and Known Answer Test (KAT) results of our KEM scheme, TiGER. This work is submitted to 'Korean Post-Quantum Cryptography Competition'(www.kpqc.or.kr).

KAT

This directory contains KAT results and scripts to perform KAT of TiGER128, TiGER192, TiGER256. In particular, run_KAT.sh repeats and updates KAT values based on latest reference implementation.

Update News

11/29/22 initial commit of reference implementation and KAT

02/21/23 v2.0 Update

07/17/23 v2.1 Update

• Fixed issue of public key and ciphertext size mismatch between specification document v2.0 and reference implementation of ciphertext and public key. (Resolve data type differences via bit/byte conversion encoding)

• Modified the implementation of storing indexes of the secret key (SK) according to the document to significantly reduce the size of SK and simplify the decapsulation operation.

• Updated based on Professor Hwajeong Seo's KPQClean project to enable easy comparison with other algorithm codes.

• Supplemented several side-channel attacks presented by Professor HeeSeok Kim (@6th KpqC workshop, July 14th).

  • Removed conditional statements from the HWT function (rejection sampling) to be executed in constant time.
  • Complemented the problem that the mask variable of D2 encoding is vulnerable to power analysis due to the Hamming weight difference (0 or -1).

09/11/23 v3.0 Update

• Corrected error in the decryption failure probability calculation formula. (Change the parameters accordingly)
• Changed the shared key (K) size in TiGER128 from 128 bits to 256 bits for security strength. (Influenced by recently released FIPS-203(draft))

Citation

If your research employs our TiGER scheme, please cite the following paper (https://eprint.iacr.org/2022/1651):

@misc{TiGER,
      author = {Seunghwan Park and Chi-Gon Jung and Aesun Park and Joongeun Choi and Honggoo Kang},
      title = {TiGER: Tiny bandwidth key encapsulation mechanism for easy miGration based on RLWE(R)},
      howpublished = {Cryptology ePrint Archive, Paper 2022/1651},
      year = {2022},
      note = {\url{https://eprint.iacr.org/2022/1651}},
      url = {https://eprint.iacr.org/2022/1651}
}