23,471 research outputs found
Greater Expectations?
Physically Unclonable Functions (PUFs) are key tools in the construction of lightweight authentication and key exchange protocols. So far, all existing PUF-based authentication protocols follow the same paradigm: A resource-constrained prover, holding a PUF, wants to authenticate to a resource-rich verifier, who has access to a database of pre-measured PUF challenge-response pairs (CRPs). In this paper we consider application scenarios where all previous PUF-based authentication schemes fail to work: The verifier is resource-constrained (and holds a PUF), while the prover is resource-rich (and holds a CRP-database). We construct the first and efficient PUF-based authentication protocol for this setting, which we call converse PUF-based authentication. We provide an extensive security analysis against passive adversaries, show that a minor modification also allows for authenticated key exchange and propose a concrete instantiation using controlled Arbiter PUFs
Computationally Sound Mechanized Proofs for Basic and Public-key Kerberos
We present a computationally sound mechanized analysis of Kerberos 5, both with and without its public-key extension PKINIT. We prove authentication and key secrecy properties using the prover CryptoVerif, which works directly in the computational model; these are the first mechanical proofs of a full industrial protocol at the computational level. We also generalize the notion of key usability and use CryptoVerif to prove that this definition is satisfied by keys in Kerberos
Mining State-Based Models from Proof Corpora
Interactive theorem provers have been used extensively to reason about
various software/hardware systems and mathematical theorems. The key challenge
when using an interactive prover is finding a suitable sequence of proof steps
that will lead to a successful proof requires a significant amount of human
intervention. This paper presents an automated technique that takes as input
examples of successful proofs and infers an Extended Finite State Machine as
output. This can in turn be used to generate proofs of new conjectures. Our
preliminary experiments show that the inferred models are generally accurate
(contain few false-positive sequences) and that representing existing proofs in
such a way can be very useful when guiding new ones.Comment: To Appear at Conferences on Intelligent Computer Mathematics 201
Efficient noninteractive certification of RSA moduli and beyond
In many applications, it is important to verify that an RSA public key (N; e) speci es a
permutation over the entire space ZN, in order to prevent attacks due to adversarially-generated
public keys. We design and implement a simple and e cient noninteractive zero-knowledge
protocol (in the random oracle model) for this task. Applications concerned about adversarial
key generation can just append our proof to the RSA public key without any other modi cations
to existing code or cryptographic libraries. Users need only perform a one-time veri cation of
the proof to ensure that raising to the power e is a permutation of the integers modulo N. For
typical parameter settings, the proof consists of nine integers modulo N; generating the proof
and verifying it both require about nine modular exponentiations.
We extend our results beyond RSA keys and also provide e cient noninteractive zero-
knowledge proofs for other properties of N, which can be used to certify that N is suitable
for the Paillier cryptosystem, is a product of two primes, or is a Blum integer. As compared to
the recent work of Auerbach and Poettering (PKC 2018), who provide two-message protocols for
similar languages, our protocols are more e cient and do not require interaction, which enables
a broader class of applications.https://eprint.iacr.org/2018/057First author draf
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