We introduce the concept of Anonymous Multi-Attribute Encryption with Range Query and Conditional Decryption (AMERQCD). In AMERQCD, a plaintext is encrypted under a point in multidimensional space. To a computationally bounded adversary, the ciphertext hides both the plaintext and the point under which it is encrypted. In a range query, a master key owner releases the decryption key for an arbi...

In order to improve the efficiency of attribute based encryption, according to the work of Li etal. [17] , a new technique is adopted to implement the revocation of attribute-based encryption. Based on the work of Green etal.[16], a ciphertext attribute based encryption (CP-ABE) scheme with outsourced revocation and decryption simultaneously is proposed. After outsourcing complex computation in...

We propose a geo-encryption protocol that allows mobile nodes to communicate securely by restricting the decryption of a message to a particular location and time period. Our protocol will handle the exchange of movement parameters, so that a sender is able to geoencrypt messages to a moving decryption zone that contains a mobile node’s estimated location. We also present methods for estimating...

Introduction Data encryption and decryption operations are basic building blocks for most security applications. For this purpose, most systems use block ciphers, such as the public AES standard. It is well known, however, that implementations of block ciphers such as AES, as well as other cryptographic algorithms, are subject to side-channel attacks [1]. These attacks allow adversaries to extr...

This paper presents an identity-based hierarchical designated decryption (IHDD) scheme which allows a message sender to generate ciphertexts that can be decrypted by (1) only a specified recipient or (2) a specified recipient and all or some of its ancestor users in the hierarchy tree. The newly proposed scheme can be considered as a combination of the hierarchical identity-based encryption (HI...

Recent years have seen a pervasive usage of mobile-based instant messaging apps, which are popularly known as chat apps. On users’ mobile devices, chat logs are usually stored encrypted. This paper is concerned with discovering the decryption key of chat-log database files as they are used by popular chat apps like WhatsApp andWeChat. We propose a systematic and generalized information-flow bas...

A threshold decryption scheme is a multi-party public key cryptosystem that allows any sufficiently large subset of participants to decrypt a ciphertext, but disallows the decryption otherwise. Many threshold cryptographic schemes have been proposed so far, but fairness is not generally considered in this earlier work. In this paper, we present fair threshold decryption schemes, where either al...

A generalized way of Vigenere cipher is proposed. Instead of using a Vigenere square for encryption and decryption, any two reversible square matrices whose rows or columns are unique are used for encryption and decryption purpose. One matrix can be easily obtained from the other and hence any one of them can be used for encryption while the other can be derived from the other for decryption. T...

During an adaptive oblivious transfer (OT), a sender has n private documents, and a receiver can adaptively fetch k documents from them such that the sender learns nothing about the receiver’s selection and the receiver learns nothing more than those k documents. Most recent fully simulatable adaptive OT schemes are based on so-called “assisted decryption” or “blind decryption”. In this paper, ...

Multi-Power RSA [1] is a fast variant of RSA [2] with a small decryption time, making it attractive for implementation on lightweight cryptographic devices such as smart cards. Hensel Lifting is a key component in the implementation of fast Multi-Power RSA Decryption. However, it is found that a näıve implementation of this algorithm is vulnerable to a host of side channel attacks, some of them...