2,026 research outputs found
ID-based Ring Signature and Proxy Ring Signature Schemes from Bilinear Pairings
In 2001, Rivest et al. firstly introduced the concept of ring signatures. A
ring signature is a simplified group signature without any manager. It protects
the anonymity of a signer. The first scheme proposed by Rivest et al. was based
on RSA cryptosystem and certificate based public key setting. The first ring
signature scheme based on DLP was proposed by Abe, Ohkubo, and Suzuki. Their
scheme is also based on the general certificate-based public key setting too.
In 2002, Zhang and Kim proposed a new ID-based ring signature scheme using
pairings. Later Lin and Wu proposed a more efficient ID-based ring signature
scheme. Both these schemes have some inconsistency in computational aspect.
In this paper we propose a new ID-based ring signature scheme and a proxy
ring signature scheme. Both the schemes are more efficient than existing one.
These schemes also take care of the inconsistencies in above two schemes.Comment: Published with ePrint Archiv
Fully Verifiable Secure Delegation of Pairing Computation: Cryptanalysis and An Efficient Construction
We address the problem of secure and verifiable delegation of general pairing computation. We first analyze some recently proposed pairing delegation schemes and present several attacks on their security and/or verifiability properties. In particular, we show that none of these achieve the claimed security and verifiability properties simultaneously. We then provide a fully verifiable secure delegation scheme under one-malicious version of a two-untrusted-program model (OMTUP). not only significantly improves the efficiency of all the previous schemes, such as fully verifiable schemes of Chevallier-Mames et al. and Canard et al. by eliminating the impractical exponentiation- and scalar-multiplication-consuming steps, but also offers for the first time the desired full verifiability property unlike other practical schemes. Furthermore, we give a more efficient and less memory consuming invocation of the subroutine for by eliminating the requirement of offline computations of modular exponentiations and scalar-multiplications. In particular, includes a fully verifiable partial delegation under the OMTUP assumption. The partial delegation of distinguishes as a useful lightweight delegation scheme when the delegator is resource-constrained (e.g. RFID tags, smart cards or sensor nodes)
Secure Delegation of Isogeny Computations and Cryptographic Applications
We address the problem of speeding up isogeny computation for supersingular elliptic curves over finite fields using untrusted computational resources like third party servers or cloud service providers (CSPs). We first propose new, efficient and secure delegation schemes. This especially enables resource-constrained devices (e.g. smart cards, RFID tags, tiny sensor nodes) to effectively deploy post-quantum isogeny-based cryptographic protocols. To the best of our knowledge, these new schemes are the first attempt to generalize the classical secure delegation schemes for group exponentiations and pairing computation to
an isogeny-based post-quantum setting. Then, we apply these secure delegation subroutines to improve the performance of supersingular isogeny-based zero-knowledge proofs of identity. Our experimental results show that, at the 128−bit quantum-security level, the proving party only needs about 3% of the original protocol cost, while the verifying party’s effort is fully
reduced to comparison operations. Lastly, we also apply our delegation schemes to decrease the computational cost of the decryption step for the NIST postquantum standardization candidate SIKE
Proxy Signature Scheme with Effective Revocation Using Bilinear Pairings
We present a proxy signature scheme using bilinear pairings that provides
effective proxy revocation. The scheme uses a binding-blinding technique to
avoid secure channel requirements in the key issuance stage. With this
technique, the signer receives a partial private key from a trusted authority
and unblinds it to get his private key, in turn, overcomes the key escrow
problem which is a constraint in most of the pairing-based proxy signature
schemes. The scheme fulfills the necessary security requirements of proxy
signature and resists other possible threats
Efficient Conditional Proxy Re-encryption with Chosen-Ciphertext Security
Recently, a variant of proxy re-encryption, named conditional proxy re-encryption (C-PRE), has been introduced. Compared with traditional proxy re-encryption, C-PRE enables the delegator to implement fine-grained delegation of decryption rights, and thus is more useful in many applications. In this paper, based on a careful observation on the existing definitions and security notions for C-PRE, we reformalize more rigorous definition and security notions for C-PRE. We further propose a more efficient C-PRE scheme, and prove its chosenciphertext security under the decisional bilinear Diffie-Hellman (DBDH) assumption in the random oracle model. In addition, we point out that a recent C-PRE scheme fails to achieve the chosen-ciphertext security
- …