94 research outputs found
Another look at HMQV
HMQV is a `hashed variant\u27 of the MQV key agreement protocol. It was recently introduced by Krawczyk, who claimed that HMQV has very significant advantages over MQV: (i) a security proof under reasonable assumptions in the (extended) Canetti-Krawczyk model for key exchange; and (ii) superior performance in some situations.
In this paper we demonstrate that HMQV is insecure by presenting realistic attacks in the Canetti-Krawczyk model that recover a victim\u27s static private key. We propose HMQV-1, a patched version of HMQV that resists our attacks (but does not have any performance advantages over MQV). We also identify the fallacies in the security proof for HMQV, critique the security model, and raise some questions about the assurances that proofs in this model can provide
On the Security of the (F)HMQV Protocol
International audienceThe HMQV protocol is under consideration for IEEE P1363 standardization. We provide a complementary analysis of the HMQV protocol. Namely, we point a Key Compromise Impersonation (KCI) attack showing that the two and three pass HMQV protocols cannot achieve their security goals. Next, we revisit the FHMQV building blocks, design and security arguments; we clarify the security and efficiency separation between HMQV and FHMQV, showing the advantages of FH-MQV over HMQV
An Elliptic Curve-based Signcryption Scheme with Forward Secrecy
An elliptic curve-based signcryption scheme is introduced in this paper that
effectively combines the functionalities of digital signature and encryption,
and decreases the computational costs and communication overheads in comparison
with the traditional signature-then-encryption schemes. It simultaneously
provides the attributes of message confidentiality, authentication, integrity,
unforgeability, non-repudiation, public verifiability, and forward secrecy of
message confidentiality. Since it is based on elliptic curves and can use any
fast and secure symmetric algorithm for encrypting messages, it has great
advantages to be used for security establishments in store-and-forward
applications and when dealing with resource-constrained devices.Comment: 13 Pages, 5 Figures, 2 Table
Obtaining a secure and efficient key agreement protocol from (H)MQV and NAXOS (extended version)
Updated (extended) and corrected version; see "Errata" and "Revisions" in the appendix for a summary of changes.LaMacchia, Lauter and Mityagin recently presented a strong security definition for authenticated key agreement strengthening the well-known Canetti-Krawczyk definition. They also described a protocol, called NAXOS, that enjoys a simple security proof in the new model. Compared to MQV and HMQV, NAXOS is less efficient and cannot be readily modified to obtain a one-pass protocol. On the other hand MQV does not have a security proof, and the HMQV security proof is extremely complicated.
This paper proposes a new authenticated key agreement protocol, called CMQV (`Combined' MQV), which incorporates design principles from MQV, HMQV and NAXOS. The new protocol achieves the efficiency of HMQV and admits a natural one-pass variant. Moreover, we present a simple and intuitive proof that CMQV is secure in the LaMacchia-Lauter-Mityagin model
ASICS: Authenticated Key Exchange Security Incorporating Certification Systems
Most security models for authenticated key exchange (AKE) do not explicitly model the associated certification system, which includes the certification authority and its behaviour. However, there are several well-known and realistic attacks on AKE protocols which exploit various forms of malicious key registration and which therefore lie outside the scope of these models. We provide the first systematic analysis of AKE security incorporating certification systems. We define a family of security models that, in addition to allowing different sets of standard AKE adversary queries, also permit the adversary to register arbitrary bitstrings as keys. For this model family, we prove generic results that enable the design and verification of protocols that achieve security even if some keys have been produced maliciously. Our approach is applicable to a wide range of models and protocols; as a concrete illustration of its power, we apply it to the CMQV protocol in the natural strengthening of the eCK model to the ASICS setting
A Reflection on the Security of Two-Party Key Establishment Protocols
Two-party key establishment has been a very fruitful research area
in cryptography, with many security models and numerous protocols
proposed. In this paper, we take another look at the YAK protocol
and the HMQV protocols and present some extended analysis. Motivated
by our analysis, we reflect on the security properties that are
desired by two-party key establishment protocols, and their
formalizations. In particular, we take into account the interface
between a key establishment protocol and the applications which may
invoke it, and emphasize the concept of session and the usage
of session identifier. Moreover, we show how to design a
two-party key establishment protocol to achieve both key
authentication and entity authentication properties in our security
model
On Vulnerabilities of the Security Association in the IEEE 802.15.6 Standard
Wireless Body Area Networks (WBAN) support a variety of real-time health
monitoring and consumer electronics applications. The latest international
standard for WBAN is the IEEE 802.15.6. The security association in this
standard includes four elliptic curve-based key agreement protocols that are
used for generating a master key. In this paper, we challenge the security of
the IEEE 802.15.6 standard by showing vulnerabilities of those four protocols
to several attacks. We perform a security analysis on the protocols, and show
that they all have security problems, and are vulnerable to different attacks
Multi-User CDH Problems and the Concrete Security of NAXOS and HMQV
We introduce CorrGapCDH, the Gap Computational Diffie-Hellman problem in the multi-user setting with Corruptions. In the random oracle model, our assumption tightly implies the security of the authenticated key exchange protocols NAXOS in the eCK model and (a simplified version of) X3DH without ephemeral key reveal. We prove hardness of CorrGapCDH in the generic group model, with optimal bounds matching the one of the discrete logarithm problem.
We also introduce CorrCRGapCDH, a stronger Challenge-Response variant of our assumption. Unlike standard GapCDH, CorrCRGapCDH implies the security of the popular AKE protocol HMQV in the eCK model, tightly and without rewinding. Again, we prove hardness of CorrCRGapCDH in the generic group model, with (almost) optimal bounds.
Our new results allow implementations of NAXOS, X3DH, and HMQV without having to adapt the group sizes to account for the tightness loss of previous reductions. As a side result of independent interest, we also obtain modular and simple security proofs from standard GapCDH with tightness loss, improving previously known bounds
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