Description
Cryptographic applications require random, unique and unpredictable keys. Since most cryptosystems need to access the key several times, it usually has to be stored permanently. This is a potential vulnerability regarding security, even if a protected memory is used as key storage. Implementing secure key generation and storage is therefore an important and challenging task which can be accomplished by Physical Unclonable Funtions (PUFs). PUFs are, typically digital, circuits that possess an intrinsic random- ness due to process variations which occur during manufacturing. They evaluate these variations and can therefore be used to generate secure cryptographic keys. It is not necessary to store these keys in a protected memory since they are implicitly stored in the PUF and can be repro- duced on demand. However, the results when reproducing a key vary, which can be interpreted as errors. Thus, error correction must be used in order to compensate this effect. We explain how methods from coding theory are applied in order to ensure reliable key reproduction. Previous work on this topic used stan- dard constructions, e.g. an ordinary concatenated scheme of a BCH and Repetition code. Based on this work we show how better results can be obtained using code classes and decoding principles not used for this sce- nario before. We exemplify these methods by specific code constructions which improve existing codes with respect to error probability, decoding complexity and codeword length. Examples based on Generalized Con- catenated, Reed-Muller and Reed-Solomon codes are given.
Next sessions
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Efficient zero-knowledge proofs and arguments in the CL framework
Speaker : Agathe Beaugrand - Institut de Mathématiques de Bordeaux
The CL encryption scheme, proposed in 2015 by Castagnos and Laguillaumie, is a linearly homomorphic encryption scheme, based on class groups of imaginary quadratic fields. The specificity of these groups is that their order is hard to compute, which means it can be considered unknown. This particularity, while being key in the security of the scheme, brings technical challenges in working with CL,[…] -
Constant-time lattice reduction for SQIsign
Speaker : Sina Schaeffler - IBM Research
SQIsign is an isogeny-based signature scheme which has recently advanced to round 2 of NIST's call for additional post-quantum signatures. A central operation in SQIsign is lattice reduction of special full-rank lattices in dimension 4. As these input lattices are secret, this computation must be protected against side-channel attacks. However, known lattice reduction algorithms like the famous[…] -
Circuit optimisation problems in the context of homomorphic encryption
Speaker : Sergiu Carpov - Arcium
Fully homomorphic encryption (FHE) is an encryption scheme that enables the direct execution of arbitrary computations on encrypted data. The first generation of FHE schemes began with Gentry's groundbreaking work in 2019. It relies on a technique called bootstrapping, which reduces noise in FHE ciphertexts. This construction theoretically enables the execution of any arithmetic circuit, but[…] -
Cycles of pairing-friendly abelian varieties
Speaker : Maria Corte-Real Santos - ENS Lyon
A promising avenue for realising scalable proof systems relies on the existence of 2-cycles of pairing-friendly elliptic curves. More specifically, such a cycle consists of two elliptic curves E/Fp and E’/Fq that both have a low embedding degree and also satisfy q = #E(Fp) and p = #E’(Fq). These constraints turn out to be rather restrictive; in the decade that has passed since 2-cycles were first[…]-
Cryptography
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