In key-insulated cryptography, there are many private keys with different indexes and a single, fixed public key. When the trust model includes multiple Certification Authorities (CAs), it can be used to shorten the verification path and mitigate the damage caused by the compromise of a CA’s private key. Existing work requires that the total number of CAs be fixed and that a trusted keystore st...

Cloud computing is an important trend that in many ways is beginning to fulfill the early promise of the Internet and creating unanticipated change in computing paradigm. As promising as cloud computing is, this paradigm brings forth new security and privacy challenges when operating in the untrusted cloud scenarios. Motivated by the challenging problem “Private Searching over Encrypted Data”, ...

The property that the stream cipher RC4 can generate the same keystream outputs under two different secret keys has been discovered recently. The principle that how the two different keys can achieve a collision is well known by investigating the key scheduling algorithm of RC4. However, how to find those colliding key pairs is a different story, which has been largely remained unexploited. Pre...

The problem of establishing a mutually held secret cryptographic key using a radio channel is addressed. The performance of a particular key distribution system is evaluated for a practical mobile radio communications system. The performance measure taken is probabilistic, and different from the Shannonmeasure of perfect secrecy. In particular, it is shown that by using a channel decoder, the p...

Revocable hierarchical identity-based encryption (RHIBE) is an extension of HIBE that supports the revocation of user’s private keys to manage the dynamic credentials of users in a system. Many different RHIBE schemes were proposed previously, but they are not efficient in terms of the private key size and the update key size since the depth of a hierarchical identity is included as a multiplic...

Moustique is one of the sixteen finalists in the eSTREAM stream cipher project. Unlike the other finalists it is a self-synchronising cipher and therefore offers very different functional properties, compared to the other candidates. We present simple related-key phenomena in Moustique that lead to the generation of strongly correlated keystreams and to powerful key-recovery attacks. Our best k...

To solve the problem of searching on encrypted data, many keyword search schemes have been proposed in recent years. The goal of such schemes is to enable a user to give an untrusted storage server the ability only to test whether an encrypted document contains a few keywords without learning anything else about the document. In this paper, we are concerned with decrypting the searched results ...

Personal information archives (PIAs) can include materials from many sources, e.g. desktop and laptop computers, mobile phones, etc. Evaluation of personal search over these collections is problematic for reasons relating to the personal and private nature of the data and associated information needs and measuring system response effectiveness. Conventional information retrieval (IR) evaluation...

This paper explores the idea of exposing sections of the private key in public-key cryptosystems whose security is based on the intractability of factorising large integers, such as RSA. While substantial work has been done in the area of partial key exposure, the aim has been to investigate the implications of inadvertant partial exposure of the private key. We focus instead on the potential a...