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.
Practical infos
Next sessions
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Efficient zero-knowledge proofs and arguments in the CL framework
Speaker : Agathe Beaugrand - Institut de Mathématiques de Bordeaux
The CL encryption scheme, proposed in 2015 by Castagnos and Laguillaumie, is a linearly homomorphic encryption scheme, based on class groups of imaginary quadratic fields. The specificity of these groups is that their order is hard to compute, which means it can be considered unknown. This particularity, while being key in the security of the scheme, brings technical challenges in working with CL,[…] -
Constant-time lattice reduction for SQIsign
Speaker : Sina Schaeffler - IBM Research
SQIsign is an isogeny-based signature scheme which has recently advanced to round 2 of NIST's call for additional post-quantum signatures. A central operation in SQIsign is lattice reduction of special full-rank lattices in dimension 4. As these input lattices are secret, this computation must be protected against side-channel attacks. However, known lattice reduction algorithms like the famous[…] -
Circuit optimisation problems in the context of homomorphic encryption
Speaker : Sergiu Carpov - Arcium
Fully homomorphic encryption (FHE) is an encryption scheme that enables the direct execution of arbitrary computations on encrypted data. The first generation of FHE schemes began with Gentry's groundbreaking work in 2019. It relies on a technique called bootstrapping, which reduces noise in FHE ciphertexts. This construction theoretically enables the execution of any arithmetic circuit, but[…] -
TBD
Speaker : Maria Corte-Real Santos - ENS Lyon
TBD-
Cryptography
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