Cryptography Stack Exchange
Cryptography Stack Exchange

Questions tagged [hqc]

Hamming Quasi-Cyclic ( HQC) is an efficient encryption scheme based on coding theory,

HQC is a code-based public-key cryptosystem with several desirable properties:

  • It is proved IND-CPA assuming the hardness of (a decisional version of) the Syndrome Decoding on structured codes. By construction, HQC perfectly fits the recent KEM-DEM transformation referred here, and allows to get a hybrid encryption scheme with strong security guarantees (IND-CCA2)
  • In contrast with most code-based cryptosystems, the assumption that the family of codes being used is indistinguishable among random codes is no longer required
  • It features a detailed and precise upper bound for the decryption failure probability analysis.

HQC Specification

3 questions
12
votes
0 answers

Requirements for security against multi-target attacks, for McEliece and other code-based cryptosystems?

This question is potentially relevant to NIST post-quantum cryptography standards, involving code-based cryptosystems such as McEliece, BIKE and HQC. For these cryptosystems, it seems that an attacker can use a "decoding one out of many" strategy as…
Ray Perlner
  • 341
  • 1
  • 5
1
vote
0 answers

HQC Duplicated Reed-Muller Codes

I'm having trouble with a definition in the HQC Specification. From page 25f., in section 2.5.5.: What does it mean to duplicate a code? Is it repeating each bit, similar to a repetition code? Further, I don't understand the type of the function…
ambiso
  • 706
  • 4
  • 13
1
vote
1 answer

Small Notation question on HQC and 2-QCSD-P Distribution

I am reading the Hamming Quasi-Cyclic (HQC) specification and just want to clarify a notation they are using. In the paragraph before Definition 2.1.14 (2-QCSD-P Distribution), for $b_1 \in \{0,1\} $ they define a set $$\mathbb{F}^{n}_{2,b1}= \{h…
grover
  • 113
  • 4