Many approaches and techniques are available in the literature for information hiding. Figure 1 shows a generic embedding and extracting scheme. The inputs to the embedding scheme are the hiding message, the cover data and an optional public or secret key K. The output is stego data, also called stego object. Inputs to the generic extracting scheme are the tested data, the secret or public key,...

We propose a new homomorphic public-key cryptosystem over arbitrary nonidentity nite group based on the di culty of the membership problem for groups of integer matrices. Besides, a homomorphic cryptosystem is designed for the rst time over nite commutative rings.

91.3 Separation of Hierarchies................................................... 1178 91.4 Walk-Through of Issuance of a Certificate Containing a CSDT............................................................ 1179 91.5 Recovery Walk-Through .................................................... 1180 91.6 Known Issues ...................................................................... 1180 9...

This survey covers basic information about public key infrastructures and summarizes the predominant technology and standards. Special attention is given to mechanisms for certificate revocation. Methods for CRL distribution and validity checking are compared. Supported by KDD R&D Laboratories, Inc.

Public key infrastructure provides a promising foundation for verifying the authenticity of communicating parties and transferring trust over the internet. The key issue in public key infrastructure is how to process certificate revocations. Previous research in this aspect has concentrated on the tradeoffs that can be made among different revocation options. No rigorous efforts have been made ...

PKIs are complex distributed systems that are responsible for giving users enough information to make reasonable trust judgments about one another. Since the currencies of PKI are trust and certificates, users who make trust decisions (often called relying parties) must do so using only some initial trust beliefs about the PKI and some pile of certificates (and other assertions) they received f...

Cryptography is, in the true sense of the word, a classic discipline: we find it in Mesopotamia and Caesar used it. Typically, the historical examples involve secret services and military. Information is exchanged amongst a limited community in which each member is to be trusted. Like Caesar’s chiffre these systems were entirely symmetric. Thus, the communicating parties needed to have a common...