Suchergebnisse

Part 1: Cryptography and Cryptanalysis ; International audience ; Malleable signatures allow the signer to control alterations to a signed document. The signer limits alterations to certain parties and to certain parts defined during signature generation. Admissible alterations do not invalidate the signature and do not involve the signer. These properties make them a versatile tool for several application domains, like e-business and health care. We implemented one secure redactable and three secure sanitizable signature schemes on secure, but computationally bounded, smart card. This allows for a secure and practically usable key management and meets legal standards of EU legislation. To gain speed we securely divided the computing tasks between the powerful host and the card; and we devise a new accumulator to yield a useable redactable scheme. The performance analysis of the four schemes shows only a small performance hit by the use of an off-the-shelf card.