19 research outputs found
Secure and Private Cloud Storage Systems with Random Linear Fountain Codes
An information theoretic approach to security and privacy called Secure And
Private Information Retrieval (SAPIR) is introduced. SAPIR is applied to
distributed data storage systems. In this approach, random combinations of all
contents are stored across the network. Our coding approach is based on Random
Linear Fountain (RLF) codes. To retrieve a content, a group of servers
collaborate with each other to form a Reconstruction Group (RG). SAPIR achieves
asymptotic perfect secrecy if at least one of the servers within an RG is not
compromised. Further, a Private Information Retrieval (PIR) scheme based on
random queries is proposed. The PIR approach ensures the users privately
download their desired contents without the servers knowing about the requested
contents indices. The proposed scheme is adaptive and can provide privacy
against a significant number of colluding servers.Comment: 8 pages, 2 figure
Capacity of Cellular Networks with Femtocache
The capacity of next generation of cellular networks using femtocaches is
studied when multihop communications and decentralized cache placement are
considered. We show that the storage capability of future network User
Terminals (UT) can be effectively used to increase the capacity in random
decentralized uncoded caching. We further propose a random decentralized coded
caching scheme which achieves higher capacity results than the random
decentralized uncoded caching. The result shows that coded caching which is
suitable for systems with limited storage capabilities can improve the capacity
of cellular networks by a factor of log(n) where n is the number of nodes
served by the femtocache.Comment: 6 pages, 2 figures, presented at Infocom Workshops on 5G and beyond,
San Francisco, CA, April 201
Coded Caching in Wireless Networks and Storage Systems
Coded caching in wireless networks and storage systems is studied. Caching based on two types of codes, index codes and fountain codes, is investigated in terms of network throughput and security. It is shown that index coding can significantly increase the multicast transmission rate in Information Centric Networks (ICN). Also, it is proved that index codes can be efficiently used to increase the multicasting transmission rate in cellular networks. It is proved that a simple graph coloring-based algorithm for index coding achieves order optimal capacity gains both for cellular and ICN networks. A new decentralized caching scheme based on Random Linear Fountain (RLF) codes is then introduced and it is shown that RLF-based coded caching performs close to optimal in terms of reducing the average number of transmission hops in wireless ad hoc and cellular networks. Therefore, considerable capacity gains can be achieved using RLF-based coded caching in wireless networks. It is shown that the RLF codes can significantly reduce the overcaching in wireless networks. Further, it is shown that using coded caching based on RLF codes we can achieve asymptotic perfect secrecy. In the limiting case of large number of coded files, the conditions of Shannon secrecy theorem are met and the problem can be modelled by a Shannon cipher system which is perfectly secure. Finally, a new storage policy based on RLF codes for storage systems along with a Private Information Retrieval (PIR) scheme for these systems is proposed and it is proved that perfect privacy and secrecy is achievable in these systems