Category: QualSec seminars

Oct 16

Seminar: François Gerard “SETLA: Signature and Encryption from Lattices” (Oct 17, 2018)

Oct 17, 2018 – 13.00 – room P.2NO8.08

Speaker: François Gerard (ULB)

Title: “SETLA: Signature and Encryption from Lattices”
Short abstract: “In data security, the main objectives one tries to achieve are confidentiality, data integrity and authentication. In a public-key setting, confidentiality is reached through asymmetric encryption and both data integrity and authentication through signature. Meeting all the security objectives for data exchange requires to use a concatenation of those primitives in an encrypt-then-sign or sign-then-encrypt fashion. Signcryption aims at providing all the security requirements in one single primitive at a lower cost than using encryption and signature together. Most existing signcryption schemes are using ElGamal-based or pairing-based techniques and thus rely on the decisional Diffie-Hellman assumption. With the current growth of a quantum threat, we seek for post-quantum counterparts to a vast majority of public-key primitives. In this work, we propose a lattice-based signcryption scheme in the random oracle model inspired from a construction of Malone-Lee. It comes in two flavors, one integrating the usual lattice-based key exchange into the signature and the other merging the scheme with a RLWE encryption. Our instantiation is based on a ring version of the scheme of Bai and Galbraith as was done in ring-TESLA and TESLA♯. It targets 128 bits of classical security and offers a save in bandwidth over a naive concatenation of state-of-the-art key exchanges and signatures from the literature. Another lightweight instantiation derived from GLP is feasible but raises long-term security concerns since the base scheme is somewhat outdated.”

May 23

Seminar: Frédéric LAFITTE “Differential properties of ARX ciphers with CryptoSAT” (May 23, 2018)

May 23, 2018 – 12.30 – room P.2NO8.08

Speaker: Frédéric LAFITTE (ULB)

Title: “Differential properties of ARX ciphers with CryptoSAT”
Short abstract: “This seminar focuses on symmetric key primitives of the ARX family. The cryptographic strength of ARX primitives comes from the combination of incompatible operators: modular addition, rotation with constant amplitude, and bit-wise exclusive OR. Despite their popularity, the resistance of ARX primitives against differential cryptanalysis is not as well understood as that of other ciphers for which design strategies allow to bound the probability of a successful attack. We show that CryptoSAT, a tool for SAT-based cryptanalysis, can be used for the verification of differential properties of ARX ciphers without sacrificing its usability.”

May 07

Seminar: Gaurav Sharma “Secure Communication on MPSoC” (May 09, 2018)

May 09, 2018 – 12.30 – room P.2NO8.08

Speaker: Gaurav Sharma (ULB)

Title: “Secure Communication on MPSoC”
Short abstract: “The recent elevation in complexity of System on Chip (SoC) needs multiple processing units to meet the latest demands. Multiple Processor System on Chip (MPSoC) is an emerging solution for this purpose. The rise in design and verification cost for complex integrated circuits and, in order to fulfill the demand of short time to market, many vendors leave the circuits vulnerable to security breaches. We are investigating to provide security of such systems with the help of affordable symmetric key cryptosystem.”

May 01

Seminar: Soultana Ellinidou “Secure SDN approach for a MPSoC platform” (May 02, 2018)

May 02, 2018 – 12.30 – room P.2NO8.08

Speaker: Soultana Ellinidou (ULB)

Title: “Secure SDN approach for a MPSoC platform”
Short abstract: “The rise of Internet of Things (IoT) and Internet of Everything (IoE) brings a wide variety of application in which traditional System on Chip (SoC) are not capable to support for that reason we propose a scalable MPSoC(Multi-Processor SoC) architecture. In order to split and address all that requirements inside our MpSoC platform we are leveraging on strategies developed within the field of Software Define Networking (SDN). SDN emerged to deal with the dynamic nature of future network functions and intelligent applications while lowering operating costs through simplifying hardware and providing flexibility on the communication inside our platform. Furthermore as far as the communication over the MPSoC platform is concerned, SDN turns the embedded system susceptible to security breaches for that reason as an initial step we will make a short introduction on the registration and authentication of our network entities by using ID-based and Group-based approach in order to provide a secure communication between them.”

Apr 24

Seminar: Rajeev Anand Sahu “Designated Verifier Blind Signature from Supersingular Isogeny” (Apr 25, 2018)

Apr 25, 2018 – 12.30 – room P.2NO8.08

Speaker: Rajeev Anand Sahu (ULB)

Title: “Designated Verifier Blind Signature from Supersingular Isogeny”
Short abstract: “Isogeny-based cryptography has recently attracted researchers as a candidate post-quantum cryptography. The first digital signature on this platform was presented by Jao and Soukharev in 2014, which is an Undeniable Signature. Currently, Srinath and Chandrasekaran have constructed Undeniable Blind Signature to provide signer’s control on the verification. Their structure involves communication overhead and the basic issues of undeniable signature. In this work, we attempt to propose a scheme of Isogeny-Based Blind Signature with requester’s control over the verification, by the means of Designated Verifier Signature.”

Apr 18

ULB Computer Science Distinguished Lecture

Prof. Joan Daemen 

April 26, 2018 at 1:30pm – ULB Plaine – Building NO – 5th floor – Solvay Room 

Column-parity mixing layers in cryptography

Mixing layers, such as MixColumns in the AES, are an essential ingredient that can be found in the round function of most modern block ciphers and permutations. We study a generalization of the mixing layer in Keccak-f, the permutation underlying the NIST standard SHA-3 and the authenticated encryption schemes Keyak and Ketje. We call this generalization column-parity mixing layers and investigate their algebraic and diffusion properties and implementation cost. We demonstrate their competitiveness by presenting a fully specified 256-bit permutation with strong bounds for differential and linear trails.

The speaker is hosted by the QualSec Research Group

Apr 12

Seminar: Bojan Spasic “Searchable Symmetric Encryption” (Apr 18, 2018)

Apr 18, 2018 – 12.30 – room P.2NO8.08

Speaker: Bojan Spasic (ULB)

Title: “Searchable Symmetric Encryption”
Short abstract: “Searchable Symmetric Encryption (SSE) has received a lot of research attention recently. To date, SSE schemes seem to provide the best tradeoffs between efficiency and security among different encrypted search solutions (e.g. property-preserving encryption, fully-homomorphic encryption, ORAM, functional encryption). Informally, SSE schemes encrypt a search structure which is outsourced to an untrusted server (e.g. in the cloud) together with the corresponding encrypted data collection. SSE enables clients to privately query the search structure in order to retrieve matching documents from the data collection. SSE has been studied in different security models and tradeoffs between security, efficiency and query expressiveness have been explored.”

Mar 12

Seminar: François Gerard “BLISS: Bimodal Lattice Signature Scheme” (Mar 14, 2018)

Mar 14, 2018 – 12.30 – room P.2NO8.08

Speaker: François Gerard (ULB)

Title: “BLISS: Bimodal Lattice Signature Scheme”
Short abstract: “In 2009, Lyubashevsky proposed the first provably secure lattice-based signature using the Fiat-Shamir paradigm. It’s security depends on a rejection step during the signature procedure. For this rejection sampling technique to be efficient, one must use a large distribution for the nonce resulting in large signatures. A few years later, Ducas and al. proposed a new scheme called BLISS optimizing this crucial step of rejection to decrease the overall size of the signature.”

Mar 06

Seminar: Helena Bruyninckx “Quantum Authentication (&Quantum Encryption)” (Mar 07, 2018)

Mar 07, 2018 – 12.30 – room P.A2.220

Speaker: Helena Bruyninckx (ULB)

Title: “Quantum Authentication (&Quantum Encryption)”

Feb 21

Seminar: Dimitrios Sisiaridis “Security Analytics: Reducing Data Complexity with Apache Spark – aggregating features and data transformation” (Feb 07, 2018)

Feb 07, 2018 – 12.30 – room P.A2.220

Speaker: Dimitrios Sisiaridis (ULB)

Title: “Security Analytics: Reducing Data Complexity with Apache Spark – aggregating features and data transformation”