We propose a public-key signature and encryption application which strongly relies on identity-based public-key cryptography. By alternately using obvious identity information like names and essential image data of the involved parties as public keys we preserve all advantages gained by identity-based public-key schemes, mainly including the absence of a public-key infrastructure [1]. On the ot...

This tutorial paper gives a fairly gentle introduction to the basic mathematics required to understand encryption systems. Three main areas are covered: modular arithmetic, prime numbers and probability theory. These should help the reader to understand how conventional and public-key encryption systems work, how they might be attacked and how to improve their security

Identity-based cryptosystems have an inherent key escrow issue, that is, the Key Generation Center (KGC) always knows user secret key. Thus, if the KGC is malicious, it can always impersonate the user. Certificateless cryptography, introduced by Al-Riyami and Paterson in 2003, is intended to solve this problem. However, in all the previously proposed certificateless schemes, it is always assume...

Key agreement is a fundamental security functionality by which pairs of nodes agree on shared keys to be used for protecting their pairwise communications. In this work we study key-agreement schemes that are well-suited for the mobile network environment. Specifically, we describe schemes with the following characteristics: • Non-interactive: any two nodes can compute a unique shared secret ke...

Long before the advent of electronic systems, different methods of information scrambling were used. Early attempts at data security in electronic computers employed some of the same transformations. Modern secret key cryptography brought much greater security, but eventually proved vulnerable to brute-force attacks. Public key cryptography has now emerged as the core technology for modern comp...

ID-based cryptosystems have many advantages over PKI based cryptosystems in key distribution, but they also have an inherent drawback of key escrow problem, i.e. users’ private keys are known to the key generation center (KGC). Therefore secure key issuing (SKI) is an important issue in ID-based cryptography. In multiple authority approach (Boneh & Franklin 2001, Chen et al. 2002), key generati...

In [3] SFLASH is presented, which supersedes SFLASH, one of the digital signature schemes in the NESSIE Portfolio of recommended cryptographic primitives [2]. We show that a known attack against the affine parts of SFLASH and SFLASH carries over immediately to the new version SFLASH: The 861 bit representing the affine parts of the secret key can easily be derived from the public key alone.

Nominally the cryptographic process is defined as follows: Given a plaintext, M, find an encryption algorithm E and an associate key K, so that M can be transformed into ciphertext C. Where the object of the transformation is to insure that without knowledge of K (or a corresponding decryption key K'), it would be practically impossible to reverse the transformation. E and K such that C=E(M,K)....

— The establishment of pairwise keys between communicating neighbor nodes in sensor networks is a challenging problem due to the unsuitability of public-key cryptographic techniques for the resource-constrained platforms of sensor networks and also due to vulnerability of physical captures of sensor nodes by an adversary/enemy. In this paper, we propose a new location-adaptive key establishment...

The Advanced Encryption Standard (AES) provides three levels of security: 128, 192, and 256 bits. Given a desired level of security for the AES, this paper discusses matching public key sizes for RSA and the ElGamal family of protocols. For the latter both traditional multiplicative groups of finite fields and elliptic curve groups are considered. The practicality of the resulting systems is co...