RERUM will be present at the ACNS conference. Henrich Pöhls will attend the 12th International Conference on Applied Cryptography and Network Security taking place from 10th of June till 13th of June in Lausanne (Swiss) and present results from RERUM.
He will present the paper ‘On Updatable Redactable Signatures’ authored by H. C. Pöhls and K. Samelin in a presentation on Friday 13th of June.
The paper is about so called redactable signatures, which allow removing parts from signed documents. In RERUM we gathered the state-of-the-art of malleable signature schemes and our analysis of security models revealed that the existing models do not capture the possibility that the signer can “update” signatures, i.e., add new elements. Neglecting this in the model, the models would tolerate that third parties can generate forgeries if they are given access to an update oracle. Moreover, the analysis showed that there are constructions which permit creating a signature by merging two redacted messages, if they stem from the same original. Again the short coming of previous models is that this is not explicitly described. The paper presents an adjusted definition that captures both possibilities. Moreover, the paper presents a provably secure construction in the standard model, which makes use of a novel trapdoor-accumulator.
For an up-to-date list of RERUM’s academic publications including DOI links, please visit the papers page.