This paper describes two cryptographic protocols for incorporating secrecy in concurrent version control systems in such a way that neither text nor passphrases are ever sent to possibly hostile servers. One of the protocols works for centralized and one for distributed version control systems. Most operations, as defined by the protocols, take linear time on the size of keys or the size of cha...

In this work, we aim to reduce the computational costs of using public-key digital signatures in securing routing protocols. Two protocols (COSP and IOSP) using one-time digital signatures are introduced to provide the functionality of public-key digital signatures. Our protocols are intended to be used in place of public-key digital signatures for signing all kinds of message exchanges among r...

When communicating using private and secure keys, there is always the doubt as to the identity of the message creator. We introduce an algorithm that uses the personal typing rhythm (keystroke dynamics) of the message originator to increase the trust of the authenticity of the message originator by the message recipient. The methodology proposes the use of a Rhythm Certificate Authority (RCA) t...

Digital signature schemes are crucial for applications in electronic commerce. The effectiveness and security of a digital signature scheme rely on its underlying public key cryptosystem. Trapdoor functions are central to public key cryptosystems. However, the modular exponentiation for RSA or the discrete logarithms for ElGamal/DSA/ECC, as the choice of the trapdoor functions, are relatively s...

robust, watermarking, invisible This paper addresses the problem of watermarking a digital image, in order to detect or verify ownership. An invisible and resilient watermark is one that is not ordinarily visible and is robust in the face of common image manipulations such as lossy compression, scaling, cropping, rotation, reflection, and brightness/contrast adjustment. A watermarking scheme is...

SUMMARY With the introduction of information and communication technologies into our homes and the different physical and communicative expressions this implies for our living spaces the concepts of being private and of being public becomes crucial. In this paper we introduce the design pattern language, developed by Christopher Alexander in the 1970s, in order to handle these problems systemat...