International Association for Cryptologic Research

Displaying 1-40 of 446 results

  • White Papers // Dec 2014

    Security Weaknesses of an "Anonymous Attribute Based Encryption: Appeared in Asiaccs'13

    Attribute-Based Encryption (ABE) has found enormous application in ne-grained access control of shared data, particularly in public cloud. The researcher proposed a scheme called match-then-decrypt, where before running the decryption algorithm the user requires to perform a match operation with attribute(s) that provides the required information to identify whether a...

    Provided By International Association for Cryptologic Research

  • White Papers // Dec 2014

    Armadillo: A Compilation Chain for Privacy Preserving Applications

    "In parallel with the research work which has lead to dramatic improvements with respect to the computational overhead of homomorphic encryption the compilation and parallelism community has also started to grow a strong interest to homomorphic encryption techniques as a new execution environment for computer programs with a highly promising...

    Provided By International Association for Cryptologic Research

  • White Papers // Dec 2014

    Cryptanalysis of Full PRIDE Block Cipher

    "Due to the rapidly growing impact of mobile phones, smart cards, RFID tags and sensor networks, lightweight cryptography which is suitable for such resource-constrained devices becomes more and more important. PRIDE is a lightweight block ciphers designed by Albrecht et al., appears in CRYPTO 2014. The designers claim that the...

    Provided By International Association for Cryptologic Research

  • White Papers // Nov 2014

    Web Tap Payment Authentication and Encryption With Zero Customer Effort

    "In tap-card-pay application (app), the authors remove the keyboarding from the customer and add the simplicity of tapping the credit card on the Smartphone when the customer tries to checkout on the merchant's webpage. They propose a public-key authentication and encryption application that secures the messages between Tap-Card-Pay application, Tap-Card-Pay...

    Provided By International Association for Cryptologic Research

  • White Papers // Oct 2014

    A Proxy Re-Encryption Scheme With the Unforgeability of Re-Encryption Keys Against Collusion Attacks

    "Proxy Re-Encryption (PRE) schemes are cryptosystems which allow a proxy who has a re-encryption key to convert a cipher-text originally encrypted for one party into a cipher-text which can be decrypted by another party. In, Hayashi et al. proposed the new security notion for PRE called ""Unforgeability of Re-encryption Keys...

    Provided By International Association for Cryptologic Research

  • White Papers // Sep 2014

    Decoy-Based Information Security

    "In this paper, the authors discuss an emerging concept of decoy-based information security, or security without computational assumptions. In particular, they show how this concept can be implemented to provide security against (passive) computationally unbounded adversary in some public-key encryption protocols. In the world of symmetric cryptography, decoy-based security finds...

    Provided By International Association for Cryptologic Research

  • White Papers // Sep 2014

    A Survey of Fault Attacks in Pairing Based Cryptography

    "The latest implementations of pairings allow efficient schemes for pairing based cryptography. These make the use of pairings suitable for small and constrained devices (Smartphone's, smart cards) in addition to more powerful platforms. As for any cryptographic algorithm which may be deployed in insecure locations, these implementations must be secure...

    Provided By International Association for Cryptologic Research

  • White Papers // Mar 2014

    Efficient Fuzzy Search on Encrypted Data

    The authors study the problem of efficient (sub-linear) fuzzy search on encrypted outsourced data, in the symmetric-key setting. In particular, a user who stores encrypted data on a remote untrusted server forms queries that enable the server to efficiently locate the records containing the requested keywords, even though the user...

    Provided By International Association for Cryptologic Research

  • White Papers // Mar 2014

    Verifiable Delegated Set Intersection Operations on Outsourced Encrypted Data

    The authors initiate the study of the following problem: suppose Alice and Bob would like to outsource their encrypted private data sets to the cloud, and they also want to conduct the set intersection operation on their plaintext data sets. The straightforward solution for them is to download their outsourced...

    Provided By International Association for Cryptologic Research

  • White Papers // Mar 2014

    Non-Interactive Cryptography in the RAM Model of Computation

    Using recently developed techniques for program obfuscation, the authors show several constructions of non-interactive cryptosystems in the Random-Access Machine (RAM) model of computation that are asymptotically more efficient than what would be obtained using generic RAM-to-circuit compilation. In particular, let T denote the running time and n the memory size...

    Provided By International Association for Cryptologic Research

  • White Papers // Feb 2014

    Outsourcing Private RAM Computation

    The authors construct the first schemes that allow a client to privately outsource arbitrary program executions to a remote server while ensuring that: the client's work is small and essentially independent of the complexity of the computation being outsourced, and the server's work is only proportional to the run-time of...

    Provided By International Association for Cryptologic Research

  • White Papers // Feb 2014

    Reducing the Overhead of Cloud MPC

    The authors present a secure Multi-Party Computation (MPC) protocol in the honest-majority setting, which aims to reduce the communication costs in the situation where there are a large number of parties (as in a cloud scenario). Their goal is to reduce the usage of point-to-point channels, so as to enable...

    Provided By International Association for Cryptologic Research

  • White Papers // Feb 2014

    Garbled RAM Revisited Part II

    In EUROCRYPT 2013, Lu and Ostrovsky proposed the notion of Garbled RAM (GRAM) programs. These GRAM programs are analogous to the classic result of Yao's garbled circuits: a large encrypted memory can first be provided to evaluator, and then a program can separately be garbled and sent to an evaluator...

    Provided By International Association for Cryptologic Research

  • White Papers // Feb 2014

    Garbled RAM Revisited Part I

    The notion of garbled Random-Access Machines (garbled RAMs) was introduced by Lu and Ostrovsky (Eurocrypt 2013). It can be seen as an analogue of Yao's garbled circuits that allows a user to garble a RAM program directly, without performing the expensive step of converting it into a circuit. In particular,...

    Provided By International Association for Cryptologic Research

  • White Papers // Jan 2014

    Improved Differential Fault Attack on MICKEY 2.0

    In this paper the authors describe several ideas related to Differential Fault Attack (DFA) on MICKEY 2.0, a stream cipher from eStream hardware profile. Using the standard assumptions for fault attacks, they first show that if the adversary can induce random single bit faults in the internal state of the...

    Provided By International Association for Cryptologic Research

  • White Papers // Dec 2013

    Power and Timing Side Channels for PUFs and their Efficient Exploitation

    The authors discuss the first power and timing side channels on Strong Physical Unclonable Functions (Strong PUFs) in the literature, and describe their efficient exploitation via adapted Machine Learning (ML) techniques. Their method is illustrated by the example of the two currently most secure (CCS 2010, IEEE T-IFS 2013) electrical...

    Provided By International Association for Cryptologic Research

  • White Papers // Dec 2013

    How to Keep a Secret: Leakage Deterring Public-key Cryptography

    How is it possible to prevent the sharing of cryptographic functions? This question appears to be fundamentally hard to address since in this setting the owner of the key is the adversary: they wishes to share a program or device that (potentially only partly) implements the users' main cryptographic functionality....

    Provided By International Association for Cryptologic Research

  • White Papers // Dec 2013

    Property Preserving Symmetric Encryption

    The authors proposed the notion of Property Preserving symmetric Encryption (PPEnc). They defined several security notions for PPEnc and studied their relationship. They also proposed a concrete scheme which preserves the orthogonality of encrypted vectors. The proposed construction is claimed to achieve the strongest security notion of property preserving encryption,...

    Provided By International Association for Cryptologic Research

  • White Papers // Dec 2013

    Weakness of Several Identity-Based Tripartite Authenticated Key Agreement Protocols

    It is necessary to guarantee confidentiality, integrity and other security services for the communication parties over the open network. Key agreement allows multi-parties exchanging public information to create a common secret key that is known only to those entities over an insecure network. In recent years, several identity-based authenticated key...

    Provided By International Association for Cryptologic Research

  • White Papers // Dec 2013

    Chosen Ciphertext Secure (CCS): Symmetric Key CCA Encryption with Minimal Ciphertext Expansion

    In some wireless environments, minimizing the size of messages is paramount due to the resulting significant energy savings. The authors present a new symmetric encryption scheme: CCS or Chosen Cipher-text Secure scheme. CCS has the property that modifications to the cipher-text randomize the resulting plaintext. Using this property, they prove...

    Provided By International Association for Cryptologic Research

  • White Papers // Dec 2013

    CBEAM: Efficient Authenticated Encryption from Feebly One-Way Functions

    The authors show how efficient and secure cryptographic mixing functions can be constructed from low-degree rotation-invariant functions rather than conventional S-Boxes. These novel functions have surprising properties; many exhibit inherent feeble (Boolean circuit) one-wayness and offer speed/area trade-offs unobtainable with traditional constructs. Recent theoretical results indicate that even if the...

    Provided By International Association for Cryptologic Research

  • White Papers // Dec 2013

    Beyond Modes: Building a Secure Record Protocol from a Cryptographic Sponge Permutation

    Blinker is a light-weight cryptographic suite and record protocol built from a single permutation. Its design is based on the sponge construction used by the SHA-3 algorithm keccak. The authors examine the SpongeWrap authenticated encryption mode and expand its padding mechanism to offer explicit domain separation and enhanced security for...

    Provided By International Association for Cryptologic Research

  • White Papers // Dec 2013

    Lattice Signatures and Bimodal Gaussians

    The authors' main result is a construction of a lattice-based digital signature scheme that represents an improvement, both in theory and in practice, over today's most efficient lattice schemes. The novel scheme is obtained as a result of a modification of the rejection sampling algorithm that is at the heart...

    Provided By International Association for Cryptologic Research

  • White Papers // Dec 2013

    Functional Encryption for Randomized Functionalities

    Originally, encryption was thought of as a way to encrypt \"Point-to-point\" communication. However, in the contemporary world with cloud computing and complex networks, it has become clear that the people need encryption to offer more functionality. In this paper, the authors present the first definitions and constructions for functional encryption...

    Provided By International Association for Cryptologic Research

  • White Papers // Dec 2013

    Verifier-Based Password-Authenticated Key Exchange: New Models and Constructions

    While Password-Authenticated Key Exchange (or PAKE) protocols have been deeply studied, a server corruption remains the main threat, with many concrete cases nowadays. Verifier-based PAKE (or VPAKE) protocols, initially called augmented-PAKE, have been proposed to limit the impact of any leakage. However, no satisfactory security model has ever been proposed...

    Provided By International Association for Cryptologic Research

  • White Papers // Dec 2013

    RDAS: A Symmetric Key Scheme for Authenticated Query Processing in Outsourced Databases

    In this paper the authors address the problem of authenticated query processing in outsourced databases. An authenticated query processing mechanism allows a client to verify the validity of the query responses that it gets from an untrusted and remote server, who stores the client's database on its behalf. They introduce...

    Provided By International Association for Cryptologic Research

  • White Papers // Dec 2013

    Towards Leakage Exploitation Rate Optimality in Template Attack

    Template attack is widely accepted to be one of the most powerful side-channel attacks, because it is usually assumed that one has a full knowledge of the targeted crypto devices and thus be well capable of characterizing the side-channel leakages. However, the question of whether template attack is really optimal...

    Provided By International Association for Cryptologic Research

  • White Papers // Dec 2013

    Formal Analysis of CRT-RSA Vigilant's Countermeasure Against the BellCoRe Attack

    In the authors' paper at PROOFS 2013, they formally studied a few known countermeasures to protect CRT- RSA against the BellCoRe fault injection attack. However, they left vigilant's countermeasure and its alleged repaired version by the researcher as future work, because the arithmetical framework of their tool was not sufficiently...

    Provided By International Association for Cryptologic Research

  • White Papers // Dec 2013

    SPHF-Friendly Non-Interactive Commitments

    In 2009, the author proposed a reasonably practical Password-Authenticated Key Exchange (PAKE) secure against adaptive adversaries in the Universal Composability (UC) framework. It exploited the canetti-fischlin methodology for commitments and the cramer-shoup Smooth Projective Hash Functions (SPHFs), following the gennaro-lindell approach for PAKE. In this paper, the authors revisit the...

    Provided By International Association for Cryptologic Research

  • White Papers // Dec 2013

    Lower Bounds in the Hardware Token Model

    A protocol for secure two-party computation allows two mutually distrustful parties to jointly compute a function f of their respective inputs, x and y, in a way that does not reveal anything beyond the value f (x; y) being computed. Soon after the introduction of this powerful notion, it was...

    Provided By International Association for Cryptologic Research

  • White Papers // Dec 2013

    Leakage Resilient Fully Homomorphic Encryption

    The authors construct the first leakage resilient variants of Fully Homomorphic Encryption (FHE) schemes. Their leakage model is bounded adaptive leakage resilience. They first construct a leakage-resilient leveled FHE scheme, meaning the scheme is both leakage resilient and homomorphic for all circuits of depth less than some pre-established maximum set...

    Provided By International Association for Cryptologic Research

  • White Papers // Dec 2013

    On the Relation of Random Grid, Probabilistic and Deterministic Visual Cryptography

    Visual cryptography is a special type of secret sharing. Two models of visual cryptography have been independently studied: deterministic visual cryptography, random grid visual cryptography, introduced by the researchers. In the context of the deterministic model, the researcher has introduced a third model, the probabilistic visual cryptography model. The connection...

    Provided By International Association for Cryptologic Research

  • White Papers // Dec 2013

    Strongly Secure One-Round Group Authenticated Key Exchange in the Standard Model

    One-round Group Authenticated Key Exchange (GAKE) protocols typically provide implicit authentication and appealing bandwidth efficiency. As a special case of GAKE - the pairing-based one-round Tripartite Authenticated Key Exchange (3AKE), recently gains much attention of research community due to its strong security. Several pairing-based one-round 3AKE protocols have recently been...

    Provided By International Association for Cryptologic Research

  • White Papers // Dec 2013

    NICV: Normalized Inter-Class Variance for Detection of Side-Channel Leakage

    Side-Channel Attacks (SCA) is considered a serious threat against embedded cryptography. Therefore security-critical chips must be tested for SCA resistance before deployment or certification. SCA are powerful but can need a lot of computation power, especially in the presence of countermeasures. The computation complexity of these attacks can be reduced...

    Provided By International Association for Cryptologic Research

  • White Papers // Dec 2013

    Iterated Group Products and Leakage Resilience Against NC1

    The interplay between group theory and computational complexity has been the source of a number of elegant constructions and computational insights. A line of work [Bar89, CM87, BT88, BC92, CL94, Cle91, and IL95] in the late 1980s gave characterizations of various complexity classes in terms of products over finite groups....

    Provided By International Association for Cryptologic Research

  • White Papers // Dec 2013

    A Note on Bilinear Groups of a Large Composite Order

    Weil pairing plays a key role in elliptic curve cryptography. The authors remark that the structure of bilinear groups of a large composite order (at least 1024 bits) could make group operation inefficient and lose the advantages of elliptic curve cryptography which gained mainly from smaller parameter size. As of...

    Provided By International Association for Cryptologic Research

  • White Papers // Dec 2013

    Constant-Round Black-Box Construction of Composable Multi-Party Computation Protocol

    The authors present the first general MPC protocol that satisfies the following: the construction is black-box, the protocol is universally composable in the plain model, and the number of rounds is constant. The security of their protocol is proven in angel-based UC security under the assumption of the existence of...

    Provided By International Association for Cryptologic Research

  • White Papers // Dec 2013

    Between a Rock and a Hard Place: Interpolating Between MPC and FHE

    In the last few years computing on encrypted data via either Fully Homomorphic Encryption (FHE) or Multi-Party Computation (MPC) has been subject to a remarkable number of improvements. Firstly, FHE was shown to be possible; and this was quickly followed by a variety of applications and performance improvements. Secondly, whilst...

    Provided By International Association for Cryptologic Research

  • White Papers // Dec 2013

    Tamper Resilient Circuits: The Adversary at the Gates

    In this paper the authors initiate the investigation of gate-tampering attacks against cryptographic circuits. Their model is motivated by the plausibility of tampering directly with circuit gates and by the increasing use of tamper resilient gates among the known constructions that are shown to be resilient against wire-tampering adversaries. They...

    Provided By International Association for Cryptologic Research

  • White Papers // Nov 2013

    Secure Multiparty Computations on BitCoin

    BitCoin is a decentralized digital currency, introduced in 2008, that has recently gained noticeable popularity. Its main features are: it lacks a central authority that controls the transactions, the list of transactions is publicly available, and its syntax allows more advanced transactions than simply transferring the money. This paper show...

    Provided By International Association for Cryptologic Research

  • White Papers // Jul 2009

    SSE Implementation of Multivariate PKCs on Modern X86 CPUs

    Multivariate Public Key Cryptosystems (MPKCs) are often touted as future-proofing against Quantum Computers. It also has been known for efficiency compared to "Traditional" alternatives. However, this advantage seems to erode with the increase of arithmetic resources in modern CPUs and improved algorithms, especially with respect to Elliptic Curve Cryptography (ECC)....

    Provided By International Association for Cryptologic Research

  • White Papers // Apr 2011

    Macro Data Load: An Efficient Mechanism for Enhancing Loaded Data Reuse

    This paper presents a study on macro data load, a novel mechanism to increase the amount of loaded data reuse within a processor. A macro data load brings into the processor a maximum-width data the cache port allows. In a 64-bit processor, for example, a byte load will bring a...

    Provided By International Association for Cryptologic Research

  • White Papers // Jan 2011

    New Constructions for Provably-Secure Time-Bound Hierarchical Key Assignment Schemes

    A time-bound hierarchical key assignment scheme is a method to assign time-dependent encryption keys to a set of classes in a partially ordered hierarchy, in such a way that each class in the hierarchy can compute the keys of all classes lower down in the hierarchy, according to temporal constraints....

    Provided By International Association for Cryptologic Research

  • White Papers // Jan 2011

    Efficient Provably-Secure Hierarchical Key Assignment Schemes

    A hierarchical key assignment scheme is a method to assign some private information and encryption keys to a set of classes in a partially ordered hierarchy, in such a way that the private information of a higher class can be used to derive the keys of all classes lower down...

    Provided By International Association for Cryptologic Research

  • White Papers // Jan 2011

    New features for JPEG Steganalysis

    The authors present in this paper a new approach for specific JPEG steganalysis and propose studying statistics of the compressed DCT coefficients. Traditionally, steganographic algorithms try to preserve statistics of the DCT and of the spatial domain, but they cannot preserve both and also control the alteration of the compressed...

    Provided By International Association for Cryptologic Research

  • White Papers // Jan 2011

    Is Privacy Compatible With Truthfulness?

    The authors investigate the mainstream interpretation of differential privacy, which says that given a differentially private mechanism, people are likely to share their data truthfully because they are at little risk of revealing their own information. They argue that this interpretation is incomplete because people value their privacy, and so...

    Provided By International Association for Cryptologic Research

  • White Papers // Sep 2009

    On Key Authentic Degree of Cryptosystem

    Against such attacks as rubber-hose attack, key authentic degree of cryptosystem is expatiated in detail, and the important significance of key authentic degree of cryptosystem is pointed out. And the key authentic degrees of modern cryptosystem under different conditions are given. Research shows that under most realistic situations, the key...

    Provided By International Association for Cryptologic Research

  • White Papers // Sep 2009

    Cryptanalysis of the Niederreiter Public Key Scheme Based on GRS Subcodes

    In this paper a new structural attack on the McEliece/Niederreiter public key cryptosystem based on subcodes of generalized Reed-Solomon codes proposed by Berger and Loidreau is described. It allows the reconstruction of the private key for almost all practical parameter choices in polynomial time with high probability. Public key cryptosystems...

    Provided By International Association for Cryptologic Research

  • White Papers // Apr 2011

    Secure Computation on the Web: Computing without Simultaneous Interaction

    Secure computation enables mutually suspicious parties to compute a joint function of their private inputs while providing strong security guarantees. Amongst other things, even if some of the participants are corrupted the output is still correctly computed, and parties do not learn anything about each other's inputs except for that...

    Provided By International Association for Cryptologic Research

  • White Papers // Dec 2010

    No-Leak Authentication by the Sherlock Holmes Method

    The authors propose a class of authentication schemes that are literally zero-knowledge, as compared to what is formally defined as "Zero-knowledge" in cryptographic literature. They call this "No-leak" authentication to distinguish from an established "Zero-knowledge" concept. The "No-leak" condition implies "Zero-knowledge" (even "Perfect zero-knowledge"), but it is actually stronger, as...

    Provided By International Association for Cryptologic Research

  • White Papers // Dec 2010

    Generic Compilers for Authenticated Key Exchange (Full Version)

    So far, all solutions proposed for authenticated key agreement combine key agreement and authentication into a single cryptographic protocol. However, in many important application scenarios, key agreement and entity authentication are clearly separated protocols. This fact enables efficient attacks on the naive combination of these protocols. In this paper, the...

    Provided By International Association for Cryptologic Research

  • White Papers // Nov 2010

    Scrutinizing Rebound Attacks: New Algorithms for Improving the Complexities

    Rebound attacks are a state-of-the-art analysis method for hash functions. These cryptanalysis methods are based on a well chosen differential path and have been applied to several hash functions from the SHA-3 competition, providing the best known analysis in these cases. In this paper the authors study rebound attacks in...

    Provided By International Association for Cryptologic Research

  • White Papers // Dec 2010

    ROTIV: RFID Ownership Transfer With Issuer Verification

    RFID tags travel between partner sites in a supply chain. For privacy reasons, each partner "Owns" the tags present at his site, i.e., the owner is the only entity able to authenticate his tags. However, when passing tags on to the next partner in the supply chain, ownership of the...

    Provided By International Association for Cryptologic Research

  • White Papers // Nov 2010

    Strongly Secure Certificate-Based Encryption Scheme With Low Communication Bandwidth

    Certificate-Based Encryption (CBE) is a new asymmetric encryption paradigm which was introduced to solve the certificate management problem in traditional Public-Key Encryption (PKE). It combines PKE and Identity-Based Encryption (IBE) while preserving some of their most attractive features. CBE provides an efficient implicit certificate mechanism which eliminates the third-party queries...

    Provided By International Association for Cryptologic Research

  • White Papers // Oct 2010

    Symmetric-Key Searchable Keyword Concealment (SSC)

    The authors discuss what is commonly known as "Searchable symmetric keywords encryption," although they prefer to replace "Encryption" with "Concealment," since many of these transformations are not (efficiently) reversible (they look more like one way hashing). The thrust of this paper is practical approaches to cryptographic solutions for cloud databases...

    Provided By International Association for Cryptologic Research

  • White Papers // Nov 2010

    Secret Key Leakage From Public Key Perturbation of DLP-Based Cryptosystems

    Finding efficient countermeasures for cryptosystems against fault attacks is challenged by a constant discovery of aws in designs. Even elements, such as public keys, that do not seem critical must be protected. From the attacks against RSA, the authors develop a new attack of DLP-based cryptosystems, built in addition on...

    Provided By International Association for Cryptologic Research

  • White Papers // Nov 2010

    The Cube Attack on Stream Cipher Trivium and Quadraticity Tests

    In 2008 I. Dinur and A. Shamir presented a new type of algebraic attack on symmetric ciphers named cube attack. The method has been applied to reduced variants of stream ciphers Trivium and Grain- 128, reduced variants of the block ciphers Serpent and CTC and to a reduced version of...

    Provided By International Association for Cryptologic Research

  • White Papers // Dec 2009

    A Strong Blind Signature Scheme Over Braid Groups

    The rapid development of quantum computing makes public key cryptosystems not based on commutative algebraic systems hot topic. Because of the non-commutativity property, the braid group with braid index more than two becomes a new candidate for constructing cryptographic protocols. A strong blind signature scheme is proposed based on the...

    Provided By International Association for Cryptologic Research

  • White Papers // Mar 2011

    Security of ECQV-Certified ECDSA Against Passive Adversaries

    The authors show that the Elliptic Curve Qu-Vanstone implicit certificate scheme (ECQV), when composed with the Elliptic Curve Digital Signature Algorithm (ECDSA), is secure against passive adversaries under the combined assumption of the random oracle model and the generic group model, - if the ECQV certificate itself is excluded from...

    Provided By International Association for Cryptologic Research

  • White Papers // Dec 2009

    On the Analysis of Cryptographic Assumptions in the Generic Ring Model

    At Eurocrypt 2009 Aggarwal and Maurer proved that breaking RSA is equivalent to factoring in the generic ring model. This model captures algorithms that may exploit the full algebraic structure of the ring of integers modulo n, but no properties of the given representation of ring elements. This interesting result...

    Provided By International Association for Cryptologic Research

  • White Papers // Sep 2009

    Security Analysis and Design of Proxy Signature Schemes Over Braid Groups

    The braid groups have attracted much attention as a new platform of constructing cryptosystems. This paper firstly analyzes the security vulnerabilities of existing proxy signature schemes over braid groups and presents feasible attacks. Then a new proxy signature scheme is proposed based on the difficulty of the conjugacy search problem...

    Provided By International Association for Cryptologic Research

  • White Papers // Feb 2011

    Information-theoretic Bounds for Differentially Private Mechanisms

    There are two active and independent lines of research that aim at quantifying the amount of information that is disclosed by computing on confidential data. Each line of research has developed its own notion of confidentiality: on the one hand, differential privacy is the emerging consensus guarantee used for privacy-preserving...

    Provided By International Association for Cryptologic Research

  • White Papers // May 2010

    Two Improved Authenticated Multiple Key Exchange Protocols

    Many authenticated multiple key exchange protocols were published in recent years. In 2008, Lee et al. presented an authenticated multiple key exchange protocol based on bilinear pairings. However, Vo et al. demonstrated an impersonation attack on the protocol, and it failed to provide authenticity and perfect forward secrecy as they...

    Provided By International Association for Cryptologic Research

  • White Papers // Feb 2010

    Correlated Product Security From Any One-Way Function and the New Notion of Decisional Correlated Product Security

    It is well-known that the k-wise product of one-way functions remains one-way, but may no longer be when the k inputs are correlated. At TCC 2009, Rosen and Segev introduced a new notion known as Correlated Product secure functions. These functions have the property that a k-wise product of them...

    Provided By International Association for Cryptologic Research

  • White Papers // Sep 2010

    Homomorphic Encryption Over Cyclic Groups Implies Chosen-Ciphertext Security

    Chosen-Ciphertext (IND-CCA) security is generally considered the right notion of security for a cryptosystem. Because of its central importance much effort has been devoted to constructing IND-CCA secure cryptosystems. In this paper, the authors consider the problem of constructing IND-CCA secure cryptosystems from (group) homomorphic encryption. The main results are...

    Provided By International Association for Cryptologic Research

  • White Papers // Dec 2010

    On Small Secret Key Attack Against RSA With High Bits Known Prime Factor

    It is well known that if the higher half bits of a prime factor are known or the secret key is small enough then the RSA cryptosystem is broken (e.g. [Coppersmith, J. Cryptology, 1997] and [Boneh-Durfee, Eurocrypt'99]). Recently, Sarkar-Maitra-Sarkar [Cryptology ePrint Archiv, 2008/315] proposed attacks against RSA under the conditions...

    Provided By International Association for Cryptologic Research

  • White Papers // May 2010

    Security Weakness of Two Authenticated Key Exchange Protocols From Pairings

    Recently, Liu proposed two authenticated multiple key exchange protocols using pairings, and claimed two protocols featured many security attributes. In this paper, the authors show that Liu's protocols are insecure. Both of Liu's protocols cannot provide perfect forward secrecy. Authenticated Key Exchange (AKE) plays an important role in secure communications....

    Provided By International Association for Cryptologic Research

  • White Papers // Jan 2011

    A New Framework for RFID Privacy

    Formal RFID security and privacy frameworks are fundamental to the design and analysis of robust RFID systems. In this paper, the authors develop a new definitional framework for RFID privacy in a rigorous and precise manner. The framework is based on a Zero-Knowledge (ZK) formulation and incorporates the notions of...

    Provided By International Association for Cryptologic Research

  • White Papers // Jul 2010

    Flaws in Differential Cryptanalysis of Reduced Round PRESENT

    In this paper, the authors have presented flaws in differential cryptanalysis of reduced round variant of PRESENT given by M.Wang for 80 bits key length and the authors have shown that it is not possible to recover 32 subkey bits by differential cryptanalysis of 16-round PRESENT as claimed. The authors...

    Provided By International Association for Cryptologic Research

  • White Papers // May 2011

    Cryptanalysis and Improvement of an Efficient CCA Secure PKE Scheme

    Recently in Chinese Journal of Computers, Kang et al. proposed an efficient CCA secure Public Key Encryption (PKE) scheme, and claimed that it is more efficient in the public/private keys than the famous CS98 and BMW05 CCA secure public key encryption scheme. However, in this paper the authors will show...

    Provided By International Association for Cryptologic Research

  • White Papers // May 2011

    Framework for Security Proofs for On-Demand Routing Protocols in Multi-Hop Wireless Networks

    The authors present a framework for security proofs for on-demand routing protocols. The framework relies on the composable cryptographic library by Backes, Pfitzmann and Waidner (BPW). The idea is to break down the security requirement against the system (the protocol) into security requirement against the elements of the system, the...

    Provided By International Association for Cryptologic Research

  • White Papers // Jun 2011

    On the (In)security of Hash-Based Oblivious RAM and a New Balancing Scheme

    With the gaining popularity of remote storage (e.g. in the Cloud), the authors consider the setting where a small, protected local machine wishes to access data on a large, untrusted remote machine. This setting was introduced in the RAM model in the context of software protection by Goldreich and Ostrovsky....

    Provided By International Association for Cryptologic Research

  • White Papers // May 2011

    Algebraic Cryptanalysis of the Round-Reduced and Side Channel Analysis of the Full PRINTCipher-48

    In this paper, the authors analyze the recently proposed light-weight block cipher PRINTCipher. Applying algebraic methods and SAT-solving they are able to break 8 rounds of PRINTCipher-48 with only 2 known plaintexts and 9 rounds under some additional assumptions. They show that it is possible to break the full 48-round...

    Provided By International Association for Cryptologic Research

  • White Papers // Jul 2011

    Cryptographic Analysis of All 4 X 4-Bit S-Boxes

    The authors present cryptanalytic results of an exhaustive search of all 16! bijective 4-bit S-Boxes. Previously affine equivalence classes have been exhaustively analyzed in 2007 work by Leander and Poschmann. They extend on this work by giving further properties of the optimal S-Box linear equivalence classes. In the main analysis...

    Provided By International Association for Cryptologic Research

  • White Papers // May 2011

    Secure Single Sign-On and Web Authentication

    Single sign-on solutions allow users to sign on only once and have their identities automatically verified by each application or service they want to access. There are few practical and secure single sign-on models, even though it is of great importance to current distributed application environments. The authors introduce the...

    Provided By International Association for Cryptologic Research

  • White Papers // Jun 2011

    Another Look at Security Definitions

    The authors take a critical look at security models that are often used to give "Provable security" guarantees. They pay particular attention to digital signatures, symmetric-key encryption, and leakage resilience. They find that there has been a surprising amount of uncertainty about what the "Right" definitions might be. Even when...

    Provided By International Association for Cryptologic Research

  • White Papers // Oct 2010

    Improved Ring Oscillator PUF: An FPGA-Friendly Secure Primitive

    In this paper, the authors analyze Ring Oscillator (RO) based Physical Unclonable Function (PUF) on FPGAs. They show that the systematic process variation adversely affects the ability of the RO-PUF to generate unique chip-signatures, and propose a compensation method to mitigate it. Moreover, a Configurable Ring Oscillator (CRO) technique is...

    Provided By International Association for Cryptologic Research

  • White Papers // Jan 2011

    Traitor Tracing Scheme With Constant Ciphertext Rate Against Powerful Pirates

    Traitor tracing schemes are used to fight piracy when distributing securely some data to multiple authorized receivers: If some receivers collude and share their decryption keys to build some pirate decoder, a tracing procedure should be able to find at least one of these "Traitors" from the pirate decoder. In...

    Provided By International Association for Cryptologic Research

  • White Papers // Jan 2011

    Perturbing and Protecting a Traceable Block Cipher

    At the Asiacrypt 2003 conference Billet and Gilbert introduce a block cipher, which, to quote them, has the following paradoxical traceability properties: it is computationally easy to derive many equivalent distinct descriptions of the same instance of the block cipher; but it is computationally difficult, given one or even up...

    Provided By International Association for Cryptologic Research

  • White Papers // Feb 2012

    A Digital Signature Scheme for Long-Term Security

    In this paper, the authors propose a signature scheme based on two intractable problems, namely the integer factorization problem and the discrete logarithm problem for elliptic curves. It is suitable for applications requiring long-term security and provides a more efficient solution than the existing ones. Many applications of the Information...

    Provided By International Association for Cryptologic Research