New threshold partially blind signature scheme without trusted center

基于间隙dIffIE-HEllMAn(gdH)群的特点,首先提出了一个有效的基于身份的部分盲签名方案,能够防止私钥产生中心(Pkg)伪造签名。而后用所提的部分盲签名方案构造了基于身份的新型门限部分盲签名方案。文中的构造思想主要基于fEldMAn的可证实秘密共享方案,具有实现简单但安全性高的特点。到目前为止,该方案是第一类用双线性对来构造的基于身份的门限部分盲签名方案。分析表明,所提方案具有部分盲性、不可伪造性和强壮性等特性,是安全、有效的。An efficient ID-based partially blind signature scheme is proposed based on gap diffie-hellman group.In this scheme, the dishonest Private Key Generator(PKG) can not impersonate any user at any time.Then a new ID-based threshold partially blind signature scheme is proposed based on the ID-based partially blind signature scheme.The main idea of the scheme is based on Feldman’s verifiable secret sharing scheme which is simple to implement with high secure character.Up to now,it is the first pairing-based cryptography on ID-based threshold partially blind signature.Analysis shows that the proposed scheme is secure and effective.It has provable security properties of blindness,unforgeability and robustness.国家自然科学基金;国家“十一五”科技支撑计划项目资助;福建省青年科技人才创新项目(No.2008F3110);福建省教育厅科技项目(No.JA08156)---

I2PA : An Efficient ABC for IoT

Internet of Things (IoT) is very attractive because of its promises. However, it brings many challenges, mainly issues about privacy preserving and lightweight cryptography. Many schemes have been designed so far but none of them simultaneously takes into account these aspects. In this paper, we propose an efficient ABC scheme for IoT devices. We use ECC without pairing, blind signing and zero knowledge proof. Our scheme supports block signing, selective disclosure and randomization. It provides data minimization and transactions' unlinkability. Our construction is efficient since smaller key size can be used and computing time can be reduced. As a result, it is a suitable solution for IoT devices characterized by three major constraints namely low energy power, small storage capacity and low computing power

Improvement of a convertible undeniable partially blind signature scheme

Undeniable signatures are the digital signatures that should be verified with the help of the signer. A signer may disavow a genuine document, if the signature is only verifiable with the aid of the signer under the condition that the signer is not honest. Undeniable signatures solve this problem by adding a new feature called the disavowal protocol in addition to the normal components of signature and verification. Disavowal protocol is able to prevent a dishonest signer from disavowing a valid signature. In some situations, an undeniable signature should be converted into a normal digital signature in order that the signature can be universally verified. Blind signatures are the digital signatures that help a user to get a signature on a message without revealing the content of the message to a signer. For the blind signatures, if the signer is able to make an agreement with the user, then the underlying signer may include some common information that is known to the user, then such signatures are partially blind signatures. Convertible undeniable partially blind signatures are of the features of undeniable signatures, blind signatures, convertible undeniable signatures, and partially blind signatures. Recently, a convertible undeniable partially blind signature scheme was presented. In this paper, we first analyse a security flaw of the convertible undeniable partially blind signature scheme. To address the security flaw, we present an improvement on the disavowal protocol. The improved scheme can prevent the signer from either proving that a given valid signature as invalid, or cheating the verifier

Critical Perspectives on Provable Security: Fifteen Years of Another Look Papers

We give an overview of our critiques of “proofs” of security and a guide to our papers on the subject that have appeared over the past decade and a half. We also provide numerous additional examples and a few updates and errata

Secure & trusted communication in emergency situations

In this paper we propose SETS, a protocol with main aim to provide secure and private communication during emergency situations. SETS achieves security of the exchanged information, attack resilience and user’s privacy. In addition, SETS can be easily adapted for mobile devices, since field experimental results show the effectiveness of the protocol on actual smart-phone platforms