in 2003, waters, felten and sahai introduced a novel cryptographic primitive called incomparable public key cryptosystem to protect anonymity of message receivers in an untrusted network. in this setting, a receiver is allowed to create many anonymous identities for himself without divulging the fact that all these identities refer to the same receiver. recently, lee and lim improved the soluti...

While cloud computing is growing at a remarkable speed, privacy issues are far from being solved. One way to diminish privacy concerns is to store data on the cloud in encrypted form. However, encryption often hinders useful computation cloud services. A theoretical approach is to employ the so-called fully homomorphic encryption, yet the overhead is so high that it is not considered a viable s...

this paper presents a new audio encryption algorithm based on permutation and residue number system. in the current approach, signal samples are combined with residue number system through permutation; therefore, a specific noise is generated. then, the audio signal is combined with the noise, generated by the algorithm, to produce a silence signal. for this purpose, the algorithm uses a predef...

mobile commerce is whatever electronic transfer or transaction via a mobile modem through a mobile net in which the true value or advance payment is done for goods, services or information. a mobile payment system should be beneficial for all related persons. for a payment system to be a successful system, end-user, seller, exporter and operators should see a additional value in it. end-user pr...

Search protocols are among the main applications of RFID systems. Since a search protocol should be able to locate a certain tag among many tags, not only it should be secure against RFID threats but also it should be affordable. In this article, an RFID-based search protocol will be presented. We use an encryption technique that is referred to as authenticated encryption in order to boost the ...

In this paper, a new method is presented for encryption of colored images. This method is based on using stack data structure and chaos which make the image encryption algorithm more efficient and robust. In the proposed algorithm, a series of data whose range is between 0 and 3 is generated using chaotic logistic system. Then, the original image is divided into four subimages, and these four i...