@misc{cryptoeprint:2021:336,
    author = {Nicolas T. Courtois and Matteo Abbondati and Hamy Ratoanina and Marek Grajek},
    title = {On Closed-Cycle Loops and Applicability of Nonlinear Product Attacks to DES},
    howpublished = {Cryptology ePrint Archive, Report 2021/336},
    year = {2021},
    url = {https://eprint.iacr.org/2021/336},
}