Post-quantum public cryptosystems introduced so far do not define a scalable key infrastructure for the quantum era. We demonstrate here certification system based on Lizama’s non-invertible exchange protocol which can be used to implement secure, scalable, interoperable and efficient (PKI). show functionality of certificates across different domains. Finally, we discuss method that enables exh...

In this paper, we study beamforming in decode-andforward (DF) relaying using multiple relays, where the source node sends a secret message as well as a non-secret message to the destination node in the presence of multiple non-colluding eavesdroppers. The non-secret message is transmitted at a fixed rate R0 and requires no protection from the eavesdroppers, whereas the secret message needs to b...

The goal of a denial-of-service (DoS) attack is to deplete the resource of a targeted server in order that its intended clients cannot obtain the services. Recently, Hwang et al. proposed an ID-based password authentication scheme using smart cards against the DoS attack. In their scheme, the major merits include: (1) mutual authentication; (2) the password guessing attack; (3) the replay attac...

Remote user authentication is an essential part in electronic commerce to identify legitimate users over the Internet. However, how to protect user privacy in the authentication has become an important issue recently. Therefore, many secure authentication schemes with smart cards have been proposed. In this paper, we will analyze the security weaknesses of two recently proposed authentication s...

Recently, many non-interactive deniable authentication (NIDA) protocols have been proposed. They are mainly composed of two types, signature-based and shared-secrecy based. After reviewing these schemes, we found that the signature-based approach can not deny the source of the message and thus can not achieve full deniability; and that, the shared-secrecy based approach suffers KCI attack altho...

In distributed systems, the smart card based password authentication, as one of the most convenient and efficient two-factor authentication mechanisms, is widely used to ensure that the protected services are not available to unauthorized users. Recently, Li et al. demonstrated that the smart card based password authentication scheme proposed by Chen et al. cannot provide perfect forward secrec...

A coupling of two distributions PX and PY is a joint distribution PXY with marginal distributions equal to PX and PY . Given marginals PX and PY and a real-valued function f(PXY ) of the joint distribution PXY , what is its minimum over all couplings PXY of PX and PY ? We study the asymptotics of such coupling problems with different f ’s. These include the maximal coupling, minimum distance co...

In this paper, we revisit formalizations of information-theoretic security for symmetric-key encryption and key agreement protocols which are very fundamental primitives in cryptography. In general, we can formalize information-theoretic security in various ways: some of them can be formalized as stand-alone security by extending (or relaxing) Shannon’s perfect secrecy; some of them can be done...

The existing certificateless signcryption schemes were designed mainly based on the traditional public key cryptography, in which the security relies on the hard problems, such as factor decomposition and discrete logarithm. However, these problems will be easily solved by the quantum computing. So the existing certificateless signcryption schemes are vulnerable to the quantum attack. Multivari...