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Implementational aspects of code-based cryptography

Abstract : We present the implementation details of Hybrid McEliece Encryption Scheme (HyMES), a improved version of the original McEliece scheme developed with Nicolas Sendrier. We present a modified version of the original scheme (which we call hybrid). It has two modifications, the first increases the information rate by putting some data in the error pattern. The second reduces the public key size by making use of a generator matrix in systematic form. We will show that the same security reduction as for the original system holds. We then describe the key generation, the encryption and the decryption algorithms and their implementation. Finally we will give some computation time for various parameters, compare them with the best known attacks, and discuss the best trade-offs. The idea of McEliece scheme is to hide the structure of the code by means of a transformation of the generator matrix. The transformed generator matrix becomes the public key and the secret key is the structure of the Goppa code together with the transformation parameters. The security relies on the fact that the decoding problem for general linear code is NP-complete. While the RSA public-key cryptosystem has become most widely used, McEliece cryptosystem has not been quite as successful. Partly because of the large public key, which impose less problem with the advance in hardware today. Our aim has been to implement a fairly fast and concise software implementation that may be used as a reference benchmark. We present the algorithmic details of our implementation as well. That is to specify the algorithms we use and the way we use them. The whole project is freely available at
keyword : codes McEliece
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Contributor : Bhaskar Biswas Connect in order to contact the contributor
Submitted on : Monday, October 4, 2010 - 11:15:38 AM
Last modification on : Friday, May 25, 2018 - 12:02:05 PM
Long-term archiving on: : Wednesday, January 5, 2011 - 2:45:42 AM


  • HAL Id : pastel-00523007, version 1



Bhaskar Biswas. Implementational aspects of code-based cryptography. Cryptography and Security [cs.CR]. Ecole Polytechnique X, 2010. English. ⟨pastel-00523007⟩



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