Symmetric authentication in a simulatable Dolev–Yao-style cryptographic library

Abstract

Tool-supported proofs of security protocols typically rely on abstractions from real cryptography by term algebras, so-called Dolev-Yao models. However, until recently it was not known whether a Dolev-Yao model could be implemented with real cryptography in a provably secure way under active attacks. For public-key encryption and signatures, this was recently shown, if one accepts a few additions to a typical Dolev-Yao model such as an operation that returns the length of a term.Here we extend this Dolev-Yao-style model, its realization, and the security proof to include a first symmetric primitive message authentication. This adds a major complication: we must deal with the exchange of secret keys. For symmetric authentication, we can allow this at any time, before or after the keys are first used for authentication, while working only with standard cryptographic assumptions.

Security in Computing Systems

“…Now the grantee (as the "active taker") is the requesting actor (rather than the "passive grantor") and, accordingly, the grantee needs a control privilege of the form [grantor,take] with the control mode take for a positive access decision: For creating, as shown in the lower half of Figure 9.26, there is a control schema create N (creator,creation) for each subset N of the pertinent set of control modes Mode with {take ,grant } Mode. 26 and their effects are visualized in Figure 9.27. 9 For the take/grant/create N class of control schemas, as specified above and visualized in Figure 9.23 and Figure 9.…”

Computational Secrecy by Typing for the Pi Calculus

“…The implementation leverages Laud's recent results [17] on secrecy by typing in the context of a simulatable cryptographic library [9,11,12]. Laud has defined a restricted variant of the spi calculus [6] with a fixed scheduling strategy and without channel mobility (so with fixed, global communication ports).…”

Authentication without Elision: Partially Specified Protocols, Associated Data, and Cryptographic Models Described by Code

“…The two works use radically different definitions and approaches. Backes and Pfitzmann employ a simulatability framework based on the cryptographic library of Backes, Pfitzmann, and Waidner [4]. While the initial result was a paper-andpencil proof, subsequent work has come to encompass the use of automated theorem-provers and frameworks backed up by cryptographic soundness guarantees; see [14,16,34,42] for work in this direction.…”