2158379
Designated-Verifier Proxy Signature Schemes
In a proxy signature scheme, a user delegates his/her signing capability to another user in such a way that the latter can sign messages on behalf of the former. In this paper, we first propose a provably secure proxy signature scheme, which is based on a two-party Schnorr signature scheme. Then, we extend this basic scheme into designated-verifier proxy signatures (DVPS). More specifically, we get two versions of DVPS: weak DVPS and strong DVPS. In both versions, the validity of a proxy signature can be checked only by the designated verifier. In a weak DVPS scheme, however, the designated verifier can further convert such proxy signatures into public verifiable ones, while a strong DVPS scheme does not have the same property even if the designated verifier’s secret key is revealed willingly or unwillingly. In addition, we briefly discuss some potential applications for DVPS.
7849675
On the Security of a Group Signature Scheme with Forward Security
A group signature scheme allows a group member of a given group to sign messages on behalf of the group in an anonymous and unlinkable way. In case of a dispute, however, a designated group manager can reveal the signer of a valid group signature. Based on Song’s forward-secure group signature schemes, Zhang, Wu, and Wang proposed a new group signature scheme with forward security at ICICS 2003. Their scheme is very efficient on both communication and computation aspects. Unfortunately, their scheme is insecure. In this paper we present a security analysis to show that their scheme is linkable, untraceable, and forgeable.
12290163
On the Security of the Lee-Hwang Group-Oriented Undeniable Signature Schemes
Undeniable signature is an intriguing concept introduced by Chaum and van Antwerpen at Crypto’89. In 1999, Lee and Hwang presented two group-oriented undeniable signature schemes with a trusted center. Their schemes are natural generalizations of Chaum’s zero knowledge undeniable signature scheme proposed in 1990. However, we find that the Lee-Hwang schemes are insecure. In this paper, we demonstrate five effective attacks on their schemes: four of them are insider universal forgeries, in which one dishonest member (maybe colluding with a verifier) can get a valid signature on any chosen massage, and another attack allows a dishonest member to prevent honest members from generating valid signatures. We also suggest heuristic improvements to overcome some of the problems involved in these attacks.
34096143
On the Security of a Certified E-Mail Scheme
As a value-added service for standard e-mail systems, a certified e-mail scheme allows a sender to deliver a message to a receiver in a fair way in the sense that either the sender obtains a receipt from the receiver and the receiver accesses the content of the e-mail simultaneously, or neither party gets the expected item. In 2000, Ferrer-Gomila et al. [11] proposed a novel certified e-mail protocol. Their scheme is both efficient and optimistic, since it has only three steps and a trusted third party is not involved in normal cases. Later, Monteiro and Dahab [16] identified an attack on Ferrer-Gomila et al.’s scheme, and further presented a modified scheme. In this paper, we show that their improvement is still insecure by successfully identifying several weaknesses and security flaws. Our attacks also apply to Ferrer-Gomila et al.’s original scheme.
8581433
An Abuse-Free Fair Contract-Signing Protocol Based on the RSA Signature
A fair contract-signing protocol allows two potentially mistrusted parities to exchange their commitments (i.e., digital signatures) to an agreed contract over the Internet in a fair way, so that either each of them obtains the other's signature, or neither party does. Based on the RSA signature scheme, a new digital contract-signing protocol is proposed in this paper. Like the existing RSA-based solutions for the same problem, our protocol is not only fair, but also optimistic, since the trusted third party is involved only in the situations where one party is cheating or the communication channel is interrupted. Furthermore, the proposed protocol satisfies a new property- abuse-freeness. That is, if the protocol is executed unsuccessfully, none of the two parties can show the validity of intermediate results to others. Technical details are provided to analyze the security and performance of the proposed protocol. In summary, we present the first abuse-free fair contract-signing protocol based on the RSA signature, and show that it is both secure and efficient.
17200585
Designated Verifier Signature Schemes: Attacks, New Security Notions and a New Construction
We show that the signer can abuse the disavowal protocol in the Jakobsson-Sako-Impagliazzo designated-verifier signature scheme. In addition, we identify a new security property—non-delegatability—that is essential for designated-verifier signatures, and show that several previously proposed designated-verifier schemes are delegatable. We give a rigorous formalisation of the security for designated-verifier signature schemes, and propose a new and efficient designated-verifier signature scheme that is provably unforgeable under a tight reduction to the Decisional Diffie-Hellman problem in the non-programmable random oracle model, and non-delegatable under a loose reduction in the programmable random oracle model. As a direct corollary, we also get a new efficient conventional signature scheme that is provably unforgeable under a tight reduction to the Decisional Diffie-Hellman problem in the non-programmable random oracle plus common reference string model.
16185032
Using Social Contextual Information to Match Criminal Identities
Criminal identity matching is crucial to crime investigation in law enforcement agencies. Existing techniques match identities that refer to the same individuals based on simple identity features. These techniques are subject to several problems. First, there is an effectiveness trade-off between the false negative and false positive rates. The improvement of one rate usually lowers the other. Second, in some situations such as identity theft, simple-feature-based techniques are unable to match identities that have completely different identity feature values. We argue that the information about the social context of an individual may provide additional information for revealing the individual’s identity, helping improve the effectiveness of identity matching techniques. We define two types of social contextual features: role-based personal features and social group features. Experiments showed that social contextual features, especially the structural similarity and the relational similarity, significantly improved the precision without lowering the recall of criminal identity matching tasks.
11895032
A Signal-Dependent Quadratic Time Frequency Distribution for Neural Source Estimation
A novel method for kernel design of a quadratic time frequency distribution (TFD) as the initial step for neural source estimation is proposed. The kernel is constructed based on the product ambiguity function (AF), which efficiently suppresses cross terms and noise in the ambiguity domain. In order to reduce the influence from the strong signal to the weak signal, an iterative approach is implemented. Simulation results validate the method and demonstrate suppression of cross terms and noise, and high resolution in the time frequency domain.
62533537
Movement-Assisted Sensor Deployment
Abstract-Adequate coverage is very important for sensor networks to fulfill the issued sensing tasks. In many working environments, it is necessary to make use of mobile sensors, which can move to the correct places to provide the required coverage. In this paper, we study the problem of placing mobile sensors to get high coverage. Based on Voronoi diagrams, we design two sets of distributed protocols for controlling the movement of sensors, one favoring communication and one favoring movement. In each set of protocols, we use Voronoi diagrams to detect coverage holes and use one of three algorithms to calculate the target locations of sensors it holes exist. Simulation results show the effectiveness of our protocols and give insight on choosing protocols and calculation algorithms under different application requirements and working conditions.
1009884
Movement-assisted sensor deployment
Abstract-Adequate coverage is very important for sensor networks to fulfill the issued sensing tasks. In many working environments, it is necessary to make use of mobile sensors, which can move to the correct places to provide the required coverage. In this paper, we study the problem of placing mobile sensors to get high coverage. Based on Voronoi diagrams, we design two sets of distributed protocols for controlling the movement of sensors, one favoring communication and one favoring movement. In each set of protocols, we use Voronoi diagrams to detect coverage holes and use one of three algorithms to calculate the target locations of sensors it holes exist. Simulation results show the effectiveness of our protocols and give insight on choosing protocols and calculation algorithms under different application requirements and working conditions.
9542759
Defect-Tolerant Nanocomputing Using Bloom Filters
The authors propose a novel defect-tolerant design methodology using Bloom filters for defect mapping for nanoscale computing devices. It is a general approach that can be used for any permanent defects incurred during the manufacturing process. The redundant design methodology does not rely on a voting strategy, thus it utilizes the device redundancy more effectively than existing approaches. Additionally, our method does not have false-positive in defect identification, i.e. it will not report a defective device as functional. Moreover, it is very space economic and can be programmed to fit different scales and characteristics of the underlying specific nanoscale devices used in the system