Biblio
We present a group signature scheme, based on the hardness of lattice problems, whose outputs are more than an order of magnitude smaller than the currently most efficient schemes in the literature. Since lattice-based schemes are also usually non-trivial to efficiently implement, we additionally provide the first experimental implementation of lattice-based group signatures demonstrating that our construction is indeed practical – all operations take less than half a second on a standard laptop. A key component of our construction is a new zero-knowledge proof system for proving that a committed value belongs to a particular set of small size. The sets for which our proofs are applicable are exactly those that contain elements that remain stable under Galois automorphisms of the underlying cyclotomic number field of our lattice-based protocol. We believe that these proofs will find applications in other settings as well. The motivation of the new zero-knowledge proof in our construction is to allow the efficient use of the selectively-secure signature scheme (i.e. a signature scheme in which the adversary declares the forgery message before seeing the public key) of Agrawal et al. (Eurocrypt 2010) in constructions of lattice-based group signatures and other privacy protocols. For selectively-secure schemes to be meaningfully converted to standard signature schemes, it is crucial that the size of the message space is not too large. Using our zero-knowledge proofs, we can strategically pick small sets for which we can provide efficient zero-knowledge proofs of membership.
State-of-the-art system-on-chip (SoC) field programmable gate arrays (FPGAs) integrate hard powerful ARM processor cores and the reconfigurable logic fabric on a single chip in addition to many commonly needed high performance and high-bandwidth peripherals. The increasing reliance on untrustworthy third-party IP (3PIP) cores, including both hardware and software in FPGA-based embedded systems has made the latter increasingly vulnerable to security attacks. Detection of trojans in 3PIPs is extremely difficult to current static detection methods since there is no golden reference model for 3PIPs. Moreover, many FPGA-based embedded systems do not have the support of security services typically found in operating systems. In this paper, we present our run-time, low-cost, and low-latency hardware and software based solution for protecting data stored in on-chip memory blocks, which has attracted little research attention. The implemented memory protection design consists of a hierarchical top-down structure and controls memory access from software IPs running on the processor and hardware IPs running in the FPGA, based on a set of rules or access rights configurable at run time. Additionally, virtual addressing and encryption of data for each memory help protect confidentiality of data in case of a failure of the memory protection unit, making it hard for the attacker to gain access to the data stored in the memory. The design is implemented and tested on the Intel (Altera) DE1-SoC board featuring a SoC FPGA that integrates a dual-core ARM processor with reconfigurable logic and hundreds of memory blocks. The experimental results and case studies show that the protection model is successful in eliminating malicious IPs from the system without need for reconfiguration of the FPGA. It prevents unauthorized accesses from untrusted IPs, while arbitrating access from trusted IPs generating legal memory requests, without incurring a serious area or latency penalty.
The aim of this paper is to find cellular automata (CA) rules that are used to describe S-boxes with good cryptographic properties and low implementation cost. Up to now, CA rules have been used in several ciphers to define an S-box, but in all those ciphers, the same CA rule is used. This CA rule is best known as the one defining the Keccak $\chi$ transformation. Since there exists no straightforward method for constructing CA rules that define S-boxes with good cryptographic/implementation properties, we use a special kind of heuristics for that – Genetic Programming (GP). Although it is not possible to theoretically prove the efficiency of such a method, our experimental results show that GP is able to find a large number of CA rules that define good S-boxes in a relatively easy way. We focus on the 4 x 4 and 5 x 5 sizes and we implement the S-boxes in hardware to examine implementation properties like latency, area, and power. Particularly interesting is the internal encoding of the solutions in the considered heuristics using combinatorial circuits; this makes it easy to approximate S-box implementation properties like latency and area a priori.
Security protocols are critical components for the construction of secure and dependable distributed applications, but their implementation is challenging and error prone. Therefore, tools for formal modelling and analysis of security protocols can be potentially very useful to support software engineers. However, despite such tools have been available for a long time, their adoption outside the research community has been very limited. In fact, most practitioners find such applications too complex and hardly usable for their daily work. In this paper, we present an Integrated Development Environment for the design, verification and implementation of security protocols, aimed at lowering the adoption barrier of formal methods tools for security. In the spirit of Model Driven Development, the environment supports the user in the specification of the model using the simple and intuitive language AnB (and its extension AnBx). Moreover, it provides a push-button solution for the formal verification of the abstract and concrete models, and for the automatic generation of Java implementation. This Eclipse-based IDE leverages on existing languages and tools for modelling and verification of security protocols, such as the AnBx Compiler and Code Generator, the model checker OFMC and the protocol verifier ProVerif.
This work describes the design, implementation, and evaluation of Λολ, a general-purpose software framework for lattice-based cryptography. The Λολ framework has several novel properties that distinguish it from prior implementations of lattice cryptosystems, including the following. Generality, modularity, concision: Λολ defines a collection of general, highly composable interfaces for mathematical operations used across lattice cryptography, allowing for a wide variety of schemes to be expressed very naturally and at a high level of abstraction. For example, we implement an advanced fully homomorphic encryption (FHE) scheme in as few as 2–5 lines of code per feature, via code that very closely matches the scheme's mathematical definition. Theory affinity: Λολ is designed from the ground-up around the specialized ring representations, fast algorithms, and worst-case hardness proofs that have been developed for the Ring-LWE problem and its cryptographic applications. In particular, it implements fast algorithms for sampling from theory-recommended error distributions over arbitrary cyclotomic rings, and provides tools for maintaining tight control of error growth in cryptographic schemes. Safety: Λολ has several facilities for reducing code complexity and programming errors, thereby aiding the correct implementation of lattice cryptosystems. In particular, it uses strong typing to statically enforce—i.e., at compile time—a wide variety of constraints among the various parameters. Advanced features: Λολ exposes the rich hierarchy of cyclotomic rings to cryptographic applications. We use this to give the first-ever implementation of a collection of FHE operations known as "ring switching," and also define and analyze a more efficient variant that we call "ring tunneling." Lastly, this work defines and analyzes a variety of mathematical objects and algorithms for the recommended usage of Ring-LWE in cyclotomic rings, which we believe will serve as a useful knowledge base for future implementations.
Searchable Symmetric Encryption aims at making possible searching over an encrypted database stored on an untrusted server while keeping privacy of both the queries and the data, by allowing some small controlled leakage to the server. Recent work shows that dynamic schemes – in which the data is efficiently updatable – leaking some information on updated keywords are subject to devastating adaptative attacks breaking the privacy of the queries. The only way to thwart this attack is to design forward private schemes whose update procedure does not leak if a newly inserted element matches previous search queries. This work proposes Sophos as a forward private SSE scheme with performance similar to existing less secure schemes, and that is conceptually simpler (and also more efficient) than previous forward private constructions. In particular, it only relies on trapdoor permutations and does not use an ORAM-like construction. We also explain why Sophos is an optimal point of the security/performance tradeoff for SSE. Finally, an implementation and evaluation results demonstrate its practical efficiency.
Honeypot is a common method of attack capture, can maximize the reduction of cyber-attacks. However, its limited application layer simulation makes it impossible to use effectively in power system. Through research on sandboxing technology, this article implements the simulated power manager applications by packaging real power manager applications, in order to expand the honeypot applied range.