Description
Nowadays, connected objects play an important role in our daily lives, providing services related to our cities, cars, homes, and health. For this purpose, they often need to be accessible by external entities, such as a garage owner (for a connected car), a postman (for a connected home), or a doctor (for a connected health device). However, it is crucial for the owner of such objects to retain control over their devices. One possibility is for the owner to define and manage access policies for their resources. In this presentation, we consider and present the use case where all the resources from connected objects are centralized on a Central Server. An owner can grant a requester access to a specific connected object based on an access policy defined by the owner and managed by an Authorization Server. Based on this use case, we enhance the Identity-Based Encryption with Wildcards primitive for access control. Specifically, we replace the key generation algorithm in the primitive with an interactive protocol involving three entities (the user, Central Server, and Authorization Server), resulting in a new cryptographic primitive that protects the privacy of both the requester and the owner. To demonstrate that this extended security still leads to practical schemes, we present the results of an implementation of our new primitive using Relic and different elliptic curves.
Infos pratiques
Prochains exposés
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Verification of Rust Cryptographic Implementations with Aeneas
Orateur : Aymeric Fromherz - Inria
From secure communications to online banking, cryptography is the cornerstone of most modern secure applications. Unfortunately, cryptographic design and implementation is notoriously error-prone, with a long history of design flaws, implementation bugs, and high-profile attacks. To address this issue, several projects proposed the use of formal verification techniques to statically ensure the[…] -
On the average hardness of SIVP for module lattices of fixed rank
Orateur : Radu Toma - Sorbonne Université
In joint work with Koen de Boer, Aurel Page, and Benjamin Wesolowski, we study the hardness of the approximate Shortest Independent Vectors Problem (SIVP) for random module lattices. We use here a natural notion of randomness as defined originally by Siegel through Haar measures. By proving a reduction, we show it is essentially as hard as the problem for arbitrary instances. While this was[…] -
Endomorphisms via Splittings
Orateur : Min-Yi Shen - No Affiliation
One of the fundamental hardness assumptions underlying isogeny-based cryptography is the problem of finding a non-trivial endomorphism of a given supersingular elliptic curve. In this talk, we show that the problem is related to the problem of finding a splitting of a principally polarised superspecial abelian surface. In particular, we provide formal security reductions and a proof-of-concept[…]-
Cryptography
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