Bertino, Ferrari and Atluri (BFA) have recently presented a model for specifying and enforcing authorization constraints for Workflow Management Systems (WFMS). The model is comprehensive and exhibits strong properties such as (1) a language to express constraints, (2) formal notions of constraint consistency and (3) algorithms for role-task and user-task assignments. In this paper, we extend t...

Recently, IACR ePrint archive posted two fully homomorphic encryption schemes without bootstrapping. In this note, we show that these schemes are trivially insecure. Furthermore, we also show that the encryption schemes of Liu and Wang [6] in CCS 2012 and the encryption scheme of Liu, Bertino, and Xun [5] in ASIACCS 2014 are insecure either.

In this paper, we present a provably secure redactable signature scheme allowing to independently redact structure and content. We identify the problems when structure is not separated from content, resulting in an attack on the scheme proposed at VLDB ’08 by Kundu and Bertino. The attack allows for changing the semantic meaning of a given tree. We introduce a rigid security model, including co...