1. Introduction. An identification scheme is a protocol which enables party A to prove his identity to party B in the presence of imposters G. This is one of the fundamental problems in cryptography, and it has numerous practical applications. In fact, whenever we present a driver's license, use a passport, pay with a credit card, enter a computer password, or punch a secret code into an automa...

We consider the search and secure problem, where intruders are to be detected in a bounded area without allowing them to escape. The problem is tackled by representing the area to be searched as a traversability graph, which is reduced to a tree graph by placing stationary robots to remove loops. The search of the remaining tree is performed using two strategies that represent different trade-o...

We study the setting in which a user stores encrypted documents (e.g. e-mails) on an untrusted server. In order to retrieve documents satisfying a certain search criterion, the user gives the server a capability that allows the server to identify exactly those documents. Work in this area has largely focused on search criteria consisting of a single keyword. If the user is actually interested i...

-Cloud computing has become an affordable technology for outsourcing data. This will help individuals and organizations to have plethora benefits such as storage, platform, software and other services. In spite of the advantages, the cloud users have security concerns as the cloud server is considered “untrusted”. In this paper we propose and build a security mechanism that provides complete se...

Schemes for encrypted search face inherent trade-offs between efficiency and privacy guarantees. Whereas search in plaintext can leverage efficient structures to achieve sublinear query time in the data size, similar performance is harder to achieve for secure search. Oblivious RAM (ORAM) techniques can provide the desired efficiency for simple look-ups, but do not address the needs of complex ...

Secure keyword search in shared infrastructures prevents stored documents from leaking sensitive information to unauthorized users. A shared index provides confidentiality if it is exclusively used by users authorized to search all the indexed documents. We introduce the Lethe indexing workflow to improve query and update efficiency in secure keyword search. The Lethe workflow clusters together...