We instantiate the hash-then-evaluate paradigm for pseudorandom functions (PRFs), $\mathsf{PRF}(k,x):=\mathsf{wPRF}(k,\mathsf{RO}(x))$, which builds a PRF $\mathsf{PRF}$ from a weak PRF $\mathsf{wPRF}$ via a public pre-processing random oracle $\mathsf{RO}$. In applications to secure multiparty computation (...$\mathsf{}$$\mathsf{}$${}_{\mathsf{}}\mathsf{}$${}_{\mathsf{}}$

In recent years, a large number of CertificateLess Aggregate Signature (CLAS) schemes have been proposed to overcome both the complexity of Public Key Infrastructure (PKI) certificate management and the key escrow problem. These CLAS schemes have mostly ...

Digital Signatures are ubiquitous in modern computing. One of the most widely used digital signature schemes is $\mathsf{ECDSA}$ due to its use in TLS, various Blockchains such as Bitcoin and Etherum, and many other applications. Yet the formal analysis of $\mathsf{...}$$\mathsf{}$

In this paper, we propose an efficient identity-based identification (IBI) scheme provably secure against impersonation under active and concurrent attacks in the standard model. Based on the proposed IBI scheme and two-tier signature technique, we ...

In this paper, we prove the quantum security of the signature scheme HAWK, proposed by Ducas, Postlethwaite, Pulles and van Woerden (ASIACRYPT 2022). More precisely, we reduce its strong unforgeability in the quantum random oracle model (QROM) to ...

We give a comprehensive characterisation of the computational power of shallow quantum circuits combined with classical computation. Specifically, for classes of search problems, we show that the following statements hold, relative to a random oracle: ...

Proof-carrying data (PCD) is a powerful cryptographic primitive that allows mutually distrustful parties to perform distributed computation in an efficiently verifiable manner. Known constructions of PCD are obtained by recursively-composing ...

Attribute-Based Encryption is widely recognized as a leap forward in the field of public key encryption. It allows to enforce an access control on encrypted data. Decryption time in ABE schemes can be long depending on the number of attributes and ...

Oblivious transfer (OT) protocol is an essential tool in cryptography that provides a wide range of applications such as secure multi-party computation, private information retrieval, private set intersection, contract signing, and privacy-preserving ...

As vehicle speed is fast and on board units' (OBUs) computing power, storage space, bandwidth and other resources are very limited, the efficiency of message transmission in vehicular ad hoc network is of great concern. Certificate‐based aggregate ...

Code‐based digital signatures suffer from two main drawbacks: large public key size and slow signature generation. Large public key size is inherent in almost all the code‐based cryptosystems and other post‐quantum alternatives; however, slow signature ...

Recently, lattice signatures based on the Fiat‐Shamir framework have seen a lot of improvements which are efficient in practice. The security of these signature schemes depends mainly on the hardness of solving short integer solutions (SIS) and/or ...

We investigate whether there are inherent limits of parallelization in the (randomized) massively parallel computation (MPC) model by comparing it with the (sequential) RAM model. As our main result, we show the existence of hard functions that are ...

A notion combined the content extraction signature and the universal designated verifier signature was put forth by Lin in 2012. Specifically, it allows an extracted signature holder to designate the signature to a prospective verifier. However, existing ...

Blind signature schemes (BSS) play a pivotal role in privacy‐oriented cryptography. However, with BSS, the signed message remains unintelligible to the signer, giving them no guarantee that the blinded message he signed actually contained valid ...

As a fundamental cryptographic primitive, oblivious transfer (OT) is developed for the sake of efficient usability and combinational feasibility. However, most OT protocols are built upon some quantum non-immune cryptosystems by assuming the hardness of ...

An aggregate signature (AS) scheme combines multiple signatures which is generated by many different users into a single one. This feature is very beneficial for diminishing storage cost, bandwidth and verification cost. Many previous attempts have been ...

Most1 certificateless signcryption schemes are based on bilinear pairing operations. Thus, the computation efficiency is low. In this paper, a new signcryption scheme without certificate and linear pairing is proposed. This scheme is proved to be secure ...

Using Shamir's secret sharing scheme to indirectly share the identity-based private key in the form of a pairing group element, we propose an efficient identity-based threshold decryption scheme from pairings and prove its security in the random oracle ...

Concurrent signatures allow two entities to generate two signatures in such a way that both signatures are ambiguous till some information is revealed by one of the parties. This kind of signature is useful in auction protocols and in a wide range of ...