We propose the first unbounded functional encryption (FE) scheme for quadratic functions and its extension, in which the sizes of messages to be encrypted are not a priori bounded. Prior to our work, all FE schemes for quadratic functions are ...${{}_{}}_{{}_{}}$${{}_{}}_{{}_{}}$${}_{{}_{}}{}_{}{}_{}{}_{}$${}_{}{}_{}$${}_{}$${}_{}$$\mathbf{}$${{}_{}}_{{}_{}}$${{}_{}}_{{}_{}}$${}_{{}_{}}{}_{}\mathbf{}{}_{}{}_{}$${}_{}{}_{}$

We introduce Multimodal Private Signature (MPS) - an anonymous signature system that offers a novel accountability feature: it allows a designated opening authority to learn some partial information $\mathsf{op}$ about the signer’s identity $\mathsf{id}$, and nothing ...$\mathsf{}\mathsf{}$$\mathsf{}\mathbf{}$$\mathsf{}{}_{}\mathsf{}$${}_{}$$\mathsf{}$

The idea of aggregate signcryption was first proposed by Selvi. The aggregation process reduces the communication overhead and hence, it is efficient in low‐bandwidth communication networks such as wireless sensor networks and vehicular ad‐hoc network ...

In 1999, Micali, Rabin and Vadhan introduced the notion of Verifiable Random Functions (VRF)\citeFOCS:MicRabVad99. VRFs compute for a given input x and a secret key $sk$ a unique function value $y=V_sk (x)$, and additionally a publicly verifiable proof ...

Blind signature (BS) schemes are a vital tool to design electronic cash (e‐cash), online transaction, electronic voting (e‐voting), digital right management (DRM) systems etc. The communication systems designed for such applications need small size and ...

Among the existing identity-based authenticated key agreement ID-AKA protocols, there are only a few of them that can resist to leakage of ephemeral secret keys, which is about the protection of the session secret key after the ephemeral secret keys of ...

This study reports on an implementation of cryptographic pairings in a general purpose computer algebra system. For security levels equivalent to the different AES flavours, we exhibit suitable curves in parametric families and show that optimal ...

In this paper we present a novel type of digital signatures, which we call blank digital signatures. The basic idea behind this scheme is that an originator can define and sign a message template, describing fixed parts of a message as well as multiple ...

Proxy re-encryption (PRE) realizes delegation of decryption rights, enabling a proxy holding a re-encryption key to convert a ciphertext originally intended for Alice into an encryption of the same message for Bob, and cannot learn anything about the ...

One concern in using cloud storage is that the sensitive data should be confidential to the servers which are outside the trust domain of data owners. Another issue is that the user may want to preserve his/her anonymity in the sharing or accessing of ...

Wireless handheld devices which support e-mail and web browsing are increasingly popular. The authenticity of the information received is important, especially for business uses. In server-aided verification (SAV), a substantial part of the verification ...

There are many bilinear pairings that naturally appear when one studies elliptic curves, abelian varieties, and related groups. Some of these pairings, notably the Weil and Lichtenbaum-Tate pairings, can be defined over finite fields and have important ...

Pairing-Based Cryptography has become relevant in industry mainly because of the increasing interest in Identity-Based protocols. A major deterrent to the general use of pairing-based protocols is the complex nature of such protocols; efficient ...

One advantage of identity-based (ID-based) primitives is the reduced overhead of maintaining multiple static key pairs and the corresponding certificates. However, should a party wish to participate in more than one protocol with the same identity (ID), ...

Signcryption is a cryptographic primitive that fulfills both the functions of digital signature and public key encryption in a logical single step,at lower computational costs and communication overheads than the traditional signature-then-encryption ...

Group signatures allow group members to anonymously sign messages in the name of a group such that only a dedicated opening authority can reveal the exact signer behind a signature. In many of the target applications, for example in sensor networks or ...

Recently, many multireceiver identity-based encryption schemes have been proposed in the literature. However, none can protect the privacy of message receivers among these schemes. In this paper, we present an anonymous multireceiver identity-based ...

This paper presents new software speed records for the computation of cryptographic pairings. More specifically, we present details of an implementation which computes the optimal ate pairing on a 257- bit Barreto-Naehrig curve in only 4,470,408 cycles ...

A common scenario in many pairing-based cryptographic protocols is that one argument in the pairing is fixed as a long term secret key or a constant parameter in the system. In these situations, the runtime of Miller's algorithm can be significantly ...

Anonymous technology can realize the privacy-preserving of the user's information, thus it plays an important role in the e-commerce application. As two important cryptographic techniques, blind signature and ring signature can realize anonymity. Thus, ...