Cryptanalysis of the Hwang-Shi Proxy Signature Scheme

[[abstract]]Recently, Hwang and Shi proposed an efficient proxy signature scheme without using one-way hash functions. In their scheme, an original signer needn't send a proxy certificate to a proxy signer through secure channels. However, there are two public key substitution methods that can be used to attack their scheme. In this article, we show that their scheme is vulnerable to the public key substitution attacks[[notice]]補正完畢[[journaltype]]國外[[incitationindex]]EI[[booktype]]紙本[[booktype]]電子版[[countrycodes]]NL

Image Tamper Detection and Recovery by Intersecting Signatures

In this paper, we propose an exact image authentication scheme that can, in the best case, detect image tampering with the accuracy of one pixel. This method is based on constructing blocks in the image in such a manner that they intersect with one another in different directions. Such a technique is very useful to identify whether an individual image pixel has been tampered with. Moreover, the tampered region can be well recovered with the embedded recover data

Improved Yen-Joye's Authenticated Multiple-key Agreement Protocol

[[abstract]]An authenticated multiple-key agreement protocol is proposed. The protocol is not only secure against the unknown-key attack but also more efficient than other protocols

An Efficient Multi-Round Anonymous Auction Protocol

[[abstract]]In this paper, we shall propose an efficient multi-round anonymous auction protocol. In the many literatures concerned, when more than one party bidding the same highest price for merchandise, all the bidders must re-participate in the auction again. It is inefficient. In this paper, the proposed protocol can make the auction easier. In our system, we first pick out the bidders offering the same highest price as the winners of the first round. Then, all the bidders need not re-participate in the auction again; only the winners of the first round have to come back for the second round

Research Issues and Challenges for Multiple Digital Signatures

[[abstract]]In this paper, we surveyed several well-known batch ver- i�cation multiple digital signatures. These schemes can batch verify multiple digital signatures which need only one veri�cation instead of t veri�cations. However, a num- ber of weaknesses of these schemes are pointed out. Ac- cording to our proposed issues and challenges, we com- pared and analyzed them. To sum up these schemes, a secure and e�cient multiple digital signatures scheme which needs only one veri�cation remains an open prob- lem

A Secure Protocol for Bluetooth Piconets Using Elliptic Curve Cryptography

[[abstract]]In this article, the authors shall propose a new method for the implementation of secure Bluetooth piconets. Two requirements for the systems must be considered, i.e., privacy and authentication. Privacy ensures that an eavesdropper cannot intercept conversations between two slaves in piconets. Authentication ensures that service is not obtained fraudulently in order to avoid charge for usage. Additionally, a new key distribution scheme is designed for practical implementation in low-cost and low-power Bluetooth piconets. The proposed method employs elliptic curve cryptography for the use in the Bluetooth network. We have proper solutions to Bluetooth devices registration and Bluetooth piconets establishment. Furthermore, compared with Seo and Lee’s protocol, the proposed scheme has a lower computation cost

An ElGamal-like Secure Channel Free Public Key Encryption with Keyword Search Scheme

[[abstract]]The idea of public key encryption with keyword search (PEKS), proposed by Boneh et al., enables one to send a trapdoor containing a encrypted keyword to query data without revealing the keyword. In Boneh et al.’s design, the trapdoor has to be transferred through a secure channel, which is both costly and inefficient. Baek et al. then proposed an efficient secure channel free public key encryption scheme with keyword search (SCF-PEKS). After that, vast amounts of research have focused on the protection against the off-line keyword guessing attack (OKGA) by enhancing the model. However, most of the PEKS/SCF-PEKS schemes developed so far are constructed by applying bilinear pairing and are susceptible to off-line keyword guessing attacks. In this paper, we propose a new SCF-PEKS scheme based on the ElGamal cryptosystem. The proposed scheme is not only secure against off-line keyword guessing attacks but also improves the efficiency