D2.1 - Report on Selected TRNG and PUF Principles

This report represents the final version of Deliverable 2.1 of the HECTOR work package WP2. It is a result of discussions and work on Task 2.1 of all HECTOR partners involved in WP2. The aim of the Deliverable 2.1 is to select principles of random number generators (RNGs) and physical unclonable functions (PUFs) that fulfill strict technology, design and security criteria. For example, the selected RNGs must be suitable for implementation in logic devices according to the German AIS20/31 standard. Correspondingly, the selected PUFs must be suitable for applying similar security approach. A standard PUF evaluation approach does not exist, yet, but it should be proposed in the framework of the project. Selected RNGs and PUFs should be then thoroughly evaluated from the point of view of security and the most suitable principles should be implemented in logic devices, such as Field Programmable Logic Arrays (FPGAs) and Application Specific Integrated Circuits (ASICs) during the next phases of the project

No Such Thing as a Small Leak: Leakage-Abuse Attacks Against Symmetric Searchable Encryption

International audienceSymmetric Searchable Encryption (SSE) schemes enable clients to securely outsource their data while maintaining the ability to perform keywords search over it. The security of these schemes is based on an explicit leakage prole. [16], has initiated the investigation into how much information could be deduced in practice from this leakage. In this paper, after recalling the leakage hierarchy introduced in 2015 by Cash et al. and the passive attacks of [16] on SSE schemes. We demonstrate the effectiveness of these attacks on a wider set of real-world datasets than previously shown. On the other hand, we show that the attacks are inefficient against some types of datasets. Finally, we used what we learned from the unsuccessful datasets to give insight into future countermeasures

Practical Passive Leakage-abuse Attacks Against Symmetric Searchable Encryption

International audienceSymmetric Searchable Encryption (SSE) schemes solve efficiently the problem of securely outsourcing client data with search functionality. These schemes are provably secure with respect to an explicit leakage profile; however, determining how much information can be inferred in practice from this leakage remains difficult. First, we recall the leakage hierarchy introduced in 2015 by Cash et al. Second, we present complete practical attacks on SSE schemes of L4, L3 and L2 leakage profiles which are deployed in commercial cloud solutions. Our attacks are passive and only assume the knowledge of a small sample of plaintexts. Moreover, we show their devastating effect on real-world data sets since, regardless of the leakage profile, an adversary knowing a mere 1% of the document set is able to retrieve 90% of documents whose content is revealed over 70%. Then, we further extend the analysis of existing attacks to highlight the gap of security that exists between L2-and L1-SSE and give some simple countermeasures to prevent our attacks