Get an update on changes of the IACR web-page here. For questions, contact newsletter (at) iacr.org. You can also receive updates via:
To receive your credentials via mail again, please click here.
You can also access the full news archive.
(NLFSRs) is attractive for stream ciphers for which high throughput
is very important. In this paper, we prove that any Galois NLFSR can be transformed into an equivalent NLFSR in the Fibonacci configuration, which is the conventional conguration of NLFSRs. The transformation is mentioned in the proof. The mapping between the initial states of the Galois NLFSR and its equivalent Fibonacci configuration is also derived. Moreover, some properties of Galois NLFSRs are presented.
face a daunting task. Not only must they understand the security
guarantees delivered by the constructions they choose,
they must also implement and combine them correctly and
Cryptographic compilers free developers from having to implement
cryptography on their own by turning high-level specifications
of security goals into efficient implementations. Yet, trusting such
tools is hard as they rely on complex mathematical
machinery and claim security properties that are subtle and difficult
In this paper, we present ZKCrypt, an optimizing cryptographic compiler that achieves an unprecedented level of assurance without sacrificing
practicality for a comprehensive class of cryptographic protocols, known
as Zero Knowledge Proofs of Knowledge. The pipeline of ZKCrypt tightly
integrates purpose-built verified compilers and verifying compilers
producing formal proofs in the CertiCrypt framework. By combining the
guarantees delivered by each stage in the pipeline, ZKCrypt provides
assurance that the implementation it outputs securely
realizes the high-level proof goal given as input. We report on the
main characteristics of ZKCrypt, highlight new definitions and concepts
at its foundations, and illustrate its applicability through a
representative example of an anonymous credential system.
scheme based on non-interactive zero knowledge proofs is proposed. The security of
the proposal is presented by sequences of games without random oracles; furthermore,
this scheme has a security proof for the property of privacy of the signer\'s identity in
comparison with the scheme proposed by Zhang et al. in 2007. In addition, this proposal
compared to the scheme presented by Huang et al. in 2011 supports non-delegatability.
The non-delegatability of our proposal is achieved since we do not use the common secret
key shared between the signer and the designated verifier in our construction. Furthermore,
if a signer delegates her signing capability which is derived from her secret key on
a specific message to a third party, then, the third party cannot generate a valid designated
verifier signature due to the relaxed special soundness of the non-interactive zero
knowledge proof. To the best of our knowledge, this construction is the first attempt to
generate a designated verifier signature scheme with non-delegatability in the standard
model, while satisfying of non-delegatability property is loose.
\\item the LRSW-based Camenisch-Lysyanskaya signature scheme
\\item the identity-based sequential aggregate signatures of Boldyreva, Gentry, O\'Neill, and Yum.
The Camenisch-Lysyanskaya signature scheme was previously proven only under the interactive LRSW assumption, and our result can be viewed as a static replacement for the LRSW assumption. The scheme of Boldyreva, Gentry, O\'Neill, and Yum was also previously proven only under an interactive assumption that was shown to hold in the generic group model. The structure of the public key signature scheme underlying the BGOY aggregate signatures is quite distinctive, and our work presents the first security analysis of this kind of structure under static assumptions.
We view our work as enhancing our understanding of the security of these signatures, and also as an important step towards obtaining proofs under the weakest possible assumptions.
Finally, we believe our work also provides a new path for proving security of signatures with embedded structure. Examples of these include:
attribute-based signatures, quoteable signatures, and signing group elements.