While non-interactive zero-knowledge (NIZK) proofs require trusted parameters, Groth, Ostrovsky and Sahai constructed non-interactive witness-indistinguishable (NIWI) proofs without any setup; they called their scheme a non-interactive zap. More recently, Bellare, Fuchsbauer and Scafuro investigated the security of NIZK in the face of parameter subversion and observe that NI zaps provide subversion-resistant soundness and WI.
Sean Rowan, Michael Clear, Mário Gerla, Meriel Huggard · 5 authors
Autonomous and self-driving vehicles are appearing on the public highways.\nThese vehicles commonly use wireless communication techniques for both\nvehicle-to-vehicle and vehicle-to-infrastructure communications. Manufacturers,\nregulators and the public are understandably concerned about large-scale\nsystems failure or malicious attack via these wireless vehicular networks. This\npaper explores the use of sensing and signalling devices that are commonly\nintegrated into modern vehicles for side-channel communication purposes.\nVisible light (using a CMOS camera) and acoustic (ultrasonic audio)\nside-channel encoding techniques are proposed, developed and evaluated in this\ncontext. The side-channels are examined both theoretically and experimentally\nand an upper bound on the line code modulation rate that is achievable with\nthese side channel schemes in the vehicular networking context is established.\nA novel inter-vehicle session key establishment protocol, leveraging both\nside-channels and a blockchain public key infrastructure, is then presented. In\nlight of the limited channel capacity and the interoperability/security\nrequirements for vehicular communications, techniques for constraining the\nthroughput requirement, providing device independence and validating the\nlocation of the intended recipient vehicle, are presented. These reduce the\nnecessary device handshake throughput to 176 bits for creating symmetric\nencryption and message authentication keys and in verifying a vehicle's\ncertificate with a recognised certification authority.\n
Open access
3 source records
cs.CR
Advanced Steganography and Watermarking Techniques
Trusted hardware systems, such as Intel's new SGX instruction set architecture extension, aim to provide strong confidentiality and integrity assurances for applications. Recent work, however, raises serious concerns about the vulnerability of such systems to side-channel attacks. We propose, formalize, and explore a cryptographic primitive called a Sealed-Glass Proof (SGP) that models computation possible in an isolated execution environment with unbounded leakage, and thus in the face of arbitrary side-channels. A SGP specifically models the capabilities of trusted hardware that can attest to correct execution of a piece of code, but whose execution is transparent, meaning that an application's secrets and state are visible to other processes on the same host. Despite this strong threat model, we show that SGPs enable a range of practical applications. Our key observation is that SGPs permit safe verifiable computing in zero-knowledge, as data leakage results only in the prover learning her own secrets. Among other applications, we describe the implementation of an end-to-end bug bounty (or zero-day solicitation) platform that couples a SGX-based SGP with a smart contract. Our platform enables a marketplace that achieves fair exchange, protects against unfair bounty withdrawals, and resists denial-of-service attacks by dishonest sellers. We also consider a slight relaxation of the SGP model that permits black-box modules instantiating minimal, side-channel resistant primitives, yielding a still broader range of applications. Our work shows how trusted hardware systems such as SGX can support trustworthy applications even in the presence of side channels.
Security and Verification in Computing
Cloud Data Security Solutions
Physical Unclonable Functions (PUFs) and Hardware Security
BACKGROUND: Proliferation and expansion of security risks necessitates new measures to ensure authenticity and validation of GMOs. Watermarking and other cryptographic methods are available which conceal and recover the original signature, but in the process reveal the authentication information. In many scenarios watermarking and standard cryptographic methods are necessary but not sufficient and new, more advanced, cryptographic protocols are necessary. RESULTS: Herein, we present a new crypto protocol, that is applicable in broader settings, and embeds the authentication string indistinguishably from a random element in the signature space and the string is verified or denied without disclosing the actual signature. Results show that in a nucleotide string of 1000, the algorithm gives a correlation of 0.98 or higher between the distribution of the codon and that of E. coli, making the signature virtually invisible. CONCLUSIONS: This algorithm may be used to securely authenticate and validate GMOs without disclosing the actual signature. While this protocol uses watermarking, its novelty is in use of more complex cryptographic techniques based on zero knowledge proofs to encode information.
Open access
Physical Unclonable Functions (PUFs) and Hardware Security
Ulrich Rührmair, J. L. Martínez-Hurtado, Xiaolin Xu, Christian Kraeh · 8 authors
We discuss the question of how physical statements can be proven over digital communication channels between two parties (a "prover" and a "verifier") residing in two separate local systems. Examples include: (i) "a certain object in the prover's system has temperature X°C", (ii) "two certain objects in the prover's system are positioned at distance X", or (iii) "a certain object in the prover's system has been irreversibly altered or destroyed". As illustrated by these examples, our treatment goes beyond classical security sensors in considering more general physical statements. Another distinctive aspect is the underlying security model: We neither assume secret keys in the prover's system, nor do we suppose classical sensor hardware in his system which is tamper-resistant and trusted by the verifier. Without an established name, we call this new type of security protocol a "virtual proof of reality" or simply a "virtual proof" (VP). In order to illustrate our novel concept, we give example VPs based on temperature sensitive integrated circuits, disordered optical scattering media, and quantum systems. The corresponding protocols prove the temperature, relative position, or destruction/modification of certain physical objects in the prover's system to the verifier. These objects (so-called "witness objects") are prepared by the verifier and handed over to the prover prior to the VP. Furthermore, we verify the practical validity of our method for all our optical and circuit-based VPs in detailed proof-of-concept experiments. Our work touches upon, and partly extends, several established concepts in cryptography and security, including physical unclonable functions, quantum cryptography, interactive proof systems, and, most recently, physical zero-knowledge proofs. We also discuss potential advancements of our method, for example "public virtual proofs" that function without exchanging witness objects between the verifier and the prover.
Open access
Physical Unclonable Functions (PUFs) and Hardware Security
Abstract. In a secure physical computation, a set of parties each have physical inputs and jointly compute a function of their inputs in a way that reveals no information to any party except for the output of the function. Recent work in CRYPTO’14 presented examples of physical zero-knowledge proofs of physical properties, a special case of secure physical two-party computation in which one party has a physical input and the second party verifies a boolean function of that input. While the work suggested a general framework for modeling and analyzing physi-cal zero-knowledge protocols, it did not provide a general theory of how to prove any physical property with zero-knowledge. This paper takes an orthogonal approach using disposable circuits (DC)—cheap hardware tokens that can be completely destroyed after a computation—an ex-tension of the familiar tamper-proof token model. In the DC model, we demonstrate that two parties can compute any function of their physical inputs in a way that leaks at most 1 bit of additional information to either party. Moreover, our result generalizes to any multi-party physical computation. Formally, our protocols achieve unconditional UC-security with input-dependent abort. 1
Abstract. LowMC is a collection of block cipher families introduced at Eurocrypt 2015 by Albrecht et al. Its design is optimized for instanti-ations of multi-party computation, fully homomorphic encryption, and zero-knowledge proofs. A unique feature of LowMC is that its internal affine layers are chosen at random, and thus each block cipher family contains a huge number of instances. The Eurocrypt paper proposed two specific block cipher families of LowMC, having 80-bit and 128-bit keys. In this paper, we mount interpolation attacks (algebraic attacks intro-duced by Jakobsen and Knudsen) on LowMC, and show that a practically significant fraction of 2−38 of its 80-bit key instances could be broken 223 times faster than exhaustive search. Moreover, essentially all instances that are claimed to provide 128-bit security could be broken about 1000 times faster. In order to obtain these results, we had to develop novel techniques and optimize the original interpolation attack in new ways. While some of our new techniques exploit specific internal properties of LowMC, others are more generic and could be applied, in principle, to any block cipher.
A Probabilistically Checkable Proof (PCP) allows a randomized verifier, with oracle access to a purported proof, to probabilistically verify an input statement of the form “x ∈ L ” by querying only few bits of the proof. A zero-knowledge PCP (ZKPCP) is a PCP with the additional guarantee that the view of any verifier querying a bounded number of proof bits can be efficiently simulated given the input x alone, where the simulated and actual views are statistically close. Originating from the first ZKPCP construction of Kilian et al. (STOC ’97), all previous constructions relied on locking schemes, an unconditionally secure oracle-based commitment primitive. The use of locking schemes makes the verifier inherently adaptive, namely, it needs to make at least two rounds of queries to the proof. Motivated by the goal of constructing non-adaptively verifiable ZKPCPs, we suggest a new technique for compiling standard PCPs into ZKPCPs. Our approach is based on leakage-resilient circuits, which are circuits that withstand certain “side-channel ” attacks, in the sense that these attacks reveal nothing about the (properly encoded) input, other than the output. We observe that the verifier’s oracle queries constitute a side-channel attack on the wire-values of the circuit
2 source records
Cryptographic Implementations and Security
Physical Unclonable Functions (PUFs) and Hardware Security
Recently, the Bitcoin cryptocurrency has been an international sensation. This paper tells the story of Bitcoin hard-ware: how a group of early-adopters self-organized and financed the creation of an entire new industry, leading to the development of machines, including ASICs, that had orders of magnitude better performance than what Dell, Intel, NVidia, AMD or Xilinx could provide. We examine this story for clues as to how we can foster greater innovation in the semiconductor industry and enable this phenomenon to occur more broadly for more application areas, spawning a new age of hardware innovation tailored to emerging application domains-an Age of Bespoke Silicon.
2 source records
Advancements in Semiconductor Devices and Circuit Design
Advanced Memory and Neural Computing
Physical Unclonable Functions (PUFs) and Hardware Security
This thesis proposes several protocols for achieving secure com- putation under concurrent and physical attacks. Secure computation allows many parties to compute a joint function of their inputs, while keeping the privacy of their input preserved. It is required that the pri- vacy one party's input is preserved even if other parties participating in the protocol collude or deviate from the protocol. In this thesis we focus on concurrent and physical attacks, where adversarial parties try to break the privacy of honest parties by ex- ploiting the network connection or physical weaknesses of the honest parties' machine. In the rst part of the thesis we discuss how to construct proto- cols that are Universally Composable (UC for short) based on physical setup assumptions. We explore the use of Physically Uncloneable Func- tions (PUFs) as setup assumption for achieving UC-secure computa- tions. PUF are physical noisy source of randomness. The use of PUFs in the UC-framework has been proposed already in [14]. However, this work assumes that all PUFs in the system are trusted. This means that, each party has to trust the PUFs generated by the other parties. In this thesis we focus on reducing the trust involved in the use of such PUFs and we introduce the Malicious PUFs model in which only PUFs generated by honest parties are assumed to be trusted. Thus the secu- rity of each party relies on its own PUF only and holds regardless of the goodness of the PUFs generated/used by the adversary. We are able to show that, under this more realistic assumption, one can achieve UC- secure computation, under computational assumptions. Moreover, we show how to achieve unconditional UC-secure commitments with (ma- licious) PUFs and with stateless tamper-proof hardware tokens. We discuss our contribution on this matter in Part I. These results are contained in papers [80] and [28]. In the second part of the thesis we focus on the concurrent setting, and we investigate on protocols achieving round optimality and black- box access to a cryptographic primitive. We study two fundamental functionalities: commitment scheme and zero knowledge, and we focus on some of the round-optimal constructions and lower bounds con- cerning both functionalities. We nd that such constructions present subtle issues. Hence, we provide new protocols that actually achieve the security guarantee promised by previous results. Concerning physical attacks, we consider adversaries able to re- set the machine of the honest party. In a reset attack a machine is forced to run a protocol several times using the same randomness. In this thesis we provide the rst construction of a witness indistinguish- able argument system that is simultaneous resettable and argument of knowledge. We discuss about this contribution in Part III, which is the content of the paper. [edited by Author]
Open access
Cryptography and Data Security
Physical Unclonable Functions (PUFs) and Hardware Security
Yi Deng, Juan A. Garay, San Ling, Huaxiong Wang · 5 authors
We consider the problem of whether there exist non-trivial constant-round public-coin zero-knowledge ZK proofs. To date, in spite of high interest in the problem, there is no definite answer to the question. We focus on the type of ZK proofs that admit a universal simulator which handles all malicious verifiers, and show a connection between the existence of such proof systems and a seemingly unrelated program functionality distinguishing problem: for a natural class of constant-round public-coin ZK proofs which we call canonical, since all known ZK protocols fall into this category, a session prefix output by the universal simulator can actually be used to distinguish a non-trivial property of the next-step functionality of the verifier's code.
Our result can be viewed as new evidence against the existence of constant-round public-coin ZK proofs, since the existence of such a proof system will bring about either one of the following: 1 a positive result for the above functionality-distinguishing problem, a typical goal in reverse-engineering attempts, commonly believed to be notoriously hard, or 2 a major paradigm shift in simulation strategies, beyond the only known straight-line simulation technique applicable to their argument counterpart, as we also argue. Note that the earlier negative evidence on constant-round public-coin ZK proofs is Barack, Lindell and Vadhan [FOCS 2003]'s result, which was based on the incomparable assumption of the existence of certain entropy-preserving hash functions, now known not to be achievable from standard assumptions via black-box reduction.
The core of our technical contribution is showing that there exists a single verifier step for constant-round public-coin ZK proofs whose functionality rather than its code is crucial for a successful simulation. This is proved by combining a careful analysis of the behavior of a set of verifiers in the above protocols and during simulation, with an improved structure-preserving version of the well-known Babai-Moran Speedup de-randomization Theorem, a key tool of independent interest.
In nanometer technology regime, design components mandate their reuse to meet the complex design challenges and hence comprise Intellectual Property (IP). Unauthorized reuse raises major security issues. IP mark(s) is embedded into a design for establishing the veracity of a legal IP owner/buyer. However, methods for trustworthy public verification of IP marks are not secure. For field-programmable gate-array (FPGA) designs, marks become prone to tampering, and even being overridden by an attacker's signature after public verification. In order to ensure trustworthy yet leakage-proof public verification based on the marks hidden in a FPGA design, we propose a zero-knowledge protocol Verify_ZKP. It is an interactive two-person game between the prover and the verifier. This protocol is fast, incurs no additional design overhead, and needs no centralized signature database. We establish that Verify_ZKP satisfies zero-knowledge property, and introduce statistical metrics to measure its robustness. We have simulated our protocol for IWLS'05 FPGA benchmarks. Experimental results on robustness and overhead are very encouraging.
Physical Unclonable Functions (PUFs) and Hardware Security
The security of electronic devices is of crucial importance to companies as well as to users.Moreover, companies that develop Intellectual Property also want to protect them from counterfeiting and overbuilding.Company profits, brand reputations and personal information of the users are at stake if there is a breach in the security of these electronic devices.In the classical approach, a system is secured by storing the cryptographic keys permanently in the non-volatile memories that are present in the security devices.However, this permanent storage of the key makes them easy targets for physical attacks; hence compromising the security of the system.A more secure, cost-effective and elegant solution to this permanent key storage is the use of Physical Unclonable Functions (PUFs).PUF is a method of producing a signature from a physical object, such as an Integrated Circuit, by relying on the non-reproducible physical attributes of a device.These signatures are unique because fabricated circuits exhibit slightly different electrical behavior from one another even if their design, mask and manufacturing process are identical.Various kinds of PUFs exist; examples are Optical PUF, Butterfly PUF and SRAM PUF.However, the start-up value based SRAM PUFs appear to be the most promising ones for usage in ICs.Although the SRAM PUFs are becoming very popular, only a little has been published in the field of modeling and analysis of their start-up behavior.Reproducing the same start-up behavior, every time the chip is powered-on, is very crucial in order to produce the same cryptographic key.This thesis proposes an analytical model for the start-up value based SRAM PUFs; it helps in understanding the impact of both non-technological parameters (such as supply voltage and temperature) as well as technological parameters (such as the geometry of the transistors and threshold voltage) on the behavior of the start-up values of an SRAM.Various experiments have been performed to analyze and quantify their impact.The results obtained indicate a major impact of the non-technology parameters.The reproducibility of start-up values becomes more likely with slower ramp-ups and lower temperatures.For example, the percentage of reproducible bits increase from 93.5% at 1s ramp-up to 96% at 10ms ramp-up.Amongst the technology parameters, it is observed that a small mismatch of 1.6% in the threshold voltage is enough to flip the start-up value of the cell for 65nm technology.These results have been validated by comparing them with actual silicon data measured at Intrinsic ID.The validation of the results proves the correctness of the analytical model proposed and gives a proof of robustness of the start-up values. Modeling SRAM Start-up Characteristics ForPhysical Unclonable Functions
Open access
Physical Unclonable Functions (PUFs) and Hardware Security
Integrated Circuits and Semiconductor Failure Analysis
Smartmeters report the current electricity consumption over the internet back to their energy providers. Finely-sampled power consumption enables the energy provider to learn the habits of the customer's household in which the smart meter is installed. This paper presents a protocol which preserves customer privacy but also allows the detection of unregistered smart meters and prevents spamming and replay attacks. A trusted-third-party is not needed. This protocol, whose security proof relies on the strong RSA assumption and the random oracle model, is based on zero-knowledge techniques. The protocol has been implemented on different hardware platforms and benchmark results are given.
Open access
Cryptography and Data Security
Smart Grid Security and Resilience
Physical Unclonable Functions (PUFs) and Hardware Security
As users have to manage an increasing number of accounts, they have to balance password security and password usability. As such, many users use insecure passwords resulting in their accounts and data being vulnerable to unauthorized accesses. In this paper, we present Physically Enhanced Authentication Ring, or PEAR, a system that alleviates this problem. We leverage Physically Unclonable Functions (PUF) to create unclonable hardware devices, which users use to authenticate. Using a hardware device, our system uses zero-knowledge proofs, which provide better security than traditional passwords, yet users must only enter a simple PIN. As such, our system is very usable and imposes little to no burden on end users and service providers. We present transaction levels on top of PEAR of as an extension and then discuss some other work that could be done in the future.
Physical Unclonable Functions (PUFs) and Hardware Security
Abstract. This paper proposes a novel method for watermarking C source code by exploiting the programming language features.The key idea of our watermarking scheme is a semantics-preserving program transformation, based on a hidden permutation of local identifiers, followed by another hidden permutation of the functions defined in the source code. This last permutation allows to encrypt the prove of ownership, in the framework of interactive zero-knowledge proof system. The proposed watermarking scheme is invisible to compilers and does not reveal any information about the watermark, its nature and its location into the program, since the zero knowledge proof is independent of the encoding and of the embedding. Finally, we introduce a third party Trusted Time-Stamp Service into the system to prevent invertibility/ambiguity attacks.
Advanced Malware Detection Techniques
Security and Verification in Computing
Physical Unclonable Functions (PUFs) and Hardware Security
Self configuring VLSI technology architectures offer a new environment for creating novel security functions. Two such functions for physical security architectures are proposed to be generated autonomously as unknown/secret internal functions. A cell-based FPGA technology architecture is deployed for generating two classes of self-constructed one-way physical secret functions, one representing a hash function and the other a ciphering function. The Hash function is a non-invertible mapping, where the cipher function should be invertible. The two sample architectures of the functions are inspired from the programmable cell structure of the selected FPGA technology. As the functions are internally created, their mapping structures can be kept completely secret and even unknown to anybody. Such units could be efficiently deployed for a novel physical security even when nothing is known about their exact architecture and mapping functions. Several new attractive application scenarios are demonstrated including a type of zero-knowledge proof of identity and clone-resistant physical units as well as secured dependency functions. It is also shown that such security mechanisms can be kept operational for some useful applications even if the secret-unknown functions are allowed to evolve and develop additional time-dependent and individual properties. Such security functions became recently possible after self-configuring VLSI architectures are available as a part of real microelectronic systems. Keywords-Identification; secret unknown hardware functions; clone-resitant units; secret-unknown physicalcipher, secret unknown hash-functions. 1.
2 source records
Physical Unclonable Functions (PUFs) and Hardware Security
This paper proposes a new zero-knowledge proof protocol of identification which combines the characteristics of the ECC and zero-knowledge proof.The proposed protocol has more advantages in the aspect of the quantity of computing and traffic.
Physical Unclonable Functions (PUFs) and Hardware Security
Reuse of intellectual property (IP) of VLSI physical design facilitates integration of more components on a single chip in shrinking time-to-market. For intellectual property protection (IPP), various kinds of IP marks are embedded into the design for establishing the veracity of a legal owner. However, public verification of IP marks is not leakage-proof. Current techniques include a sufficiently large set of public marks containing a header and a message body in addition to private ones to facilitate only public verification at the cost of significant increase in design overhead. But these techniques are not effective, as attackers manage to obtain potential clues to tamper public marks rendering public verification invalid and may also suitably override the marks to include own signature resulting in wrong public identification of IP owner. Here we propose a zero-knowledge protocol to ensure robust and absolutely leakage proof convincing public verification with the help of private marks. We have tested our protocol for FPGA benchmarks. The results on overhead and robustness are encouraging.
Physical Unclonable Functions (PUFs) and Hardware Security
Zero-knowledge proof (ZKP) based authentication protocols provide a smart way to prove an identity of a node without giving away any information about the secret of that identity. There are many advantages as well as disadvantages to using this protocol over other authentication schemes, and challenges to overcome in order to make it practical for general use. This chapter examines the viability of ZKPs for use in authentication protocols in networks. It is concluded that nodes in a network can achieve a desired level of security by trading off key size, interactivity, and other parameters of the authentication protocol. This chapter also provides data analysis that can be useful in determining expected authentication times based on device capabilities. Pseudocode is provided for implementing a graph-based ZKP on small or limited processing devices.Request access from your librarian to read this chapter's full text.
2 source records
Cryptography and Data Security
Privacy-Preserving Technologies in Data
Physical Unclonable Functions (PUFs) and Hardware Security
An efficient computational Zero-Knowledge Proof of Knowledge whose security relies on the NP-completeness of the Independent Set Problem is presented here. The proposed algorithm is constructed from a bit commitment scheme based on the hardness of the Discrete Logarithm Problem, which guarantees the fulfillment of soundness, completeness and computational zero-knowledge properties, and allows avoiding the use of the Graph Isomorphism Problem, which is present in every known Zero-Knowledge Proofs for the Independent Set Problem.
Cryptography and Data Security
Complexity and Algorithms in Graphs
Physical Unclonable Functions (PUFs) and Hardware Security