Electronic signatures are an established method to ensure the integrity and accountability of electronic transactions. Realizing their potential, the European Parliament and the Council enacted the directive 1999/93/EC in 1999, providing legal requirements for a common introduction of electronic signatures in Europe. However, so far the signature market has failed miserably. Mobile electronic s...

Homomorphic signature schemes are an important primitive for many applications and since their introduction numerous solutions have been presented. Thus, in this work we provide the first exhaustive, complete, and up-to-dated survey about the state of the art of homomorphic signature schemes. First, the general framework where homomorphic signatures are defined is described and it is shown how ...

the results of examination of annual financial statements by independent experts (auditors) are presented in reports. we have tried to examine and evaluate the activities of two important professions of accountancy and auditing in iran, in preparing and validating annual financial statements, and relate these evaluations to group behavior of share – holders and analyses of stock – brokers. for ...

At the fourth ACM conference on electronic commerce (EC’03), S. Han, K.Y. Yeung and J. Wang proposed an ID-based confirmer signature scheme using pairings (actually, this is an ID-based undeniable signature scheme). However, in this paper, we will show that this signature scheme is not secure. The signer can deny any signature, even this signature is his valid signature and any one can forge a ...

Long-term storage of electronically signed emails will be fundamental for various next generation services in eBusiness and eGovernment. Practical usefulness of email transactions requires the ability to keep a signed email verifiable for long-term periods. This paper presents solutions to this and similar problems. State of the art long-term storage technology is combined with the latest techn...