A PrivacyPreserving Scheme Based on Fragments Storage and Fragments Recombination in CCN ContentCentric Networking (CCN) is one of the most important nextgeneration Internet architectures. The innetwork caching mechanism in CCN can bring higher efficiency and lower traffic to the network in terms of content distribution, but it also poses a great privacy risks. In this paper, we propose a privacypreserving scheme based on fragments storage and fragments recombination (FSu0026FR) to solve the useru0027s privacy leakage problem caused by timing attack in CCN. Firstly, the content in the network can be divided into different privacy levels according to the content provider, content consumer and router. Secondly, the optimal number of content fragments can be obtained by binary linear regression model based on content popularity, node betweenness and content privacy levels. Finally, the FSu0026FR algorithm is proposed and applied to the private content for content distribution and achieving finegrained privacy protection. The simulation results show that the proposed scheme is secure yet highly efficient again timing attack compared to randomK delay algorithm. More specifically, the FSu0026FR algorithm can make the roundtrip delays obtained by the attacker requesting the same content change, and then protect usersxe2x80x99 behavior privacy without sacrificing distribution performance.

Efficient Lattice CPABE AC Scheme Supporting ReducedOBDD Structure for CCNNDN In line with the proposed 5th Generation network, content centric networknamed data networking (CCNNDN) has been offered as one of the promising paradigms to cope with the communication needs of future realistic network communications. CCNNDN allows network communication based on content names and also allows users to obtain information from any of the nearest intermediary caches on the network. Due to that, the ability of cached content to protect itself is essential since contents can be cached on any node everywhere, and publishers may not have total control over their own published data. The attribute based encryption (ABE) scheme is a preferable approach, identified to enable cached contents to be selfsecured since it has a special property of encryption with policies. However, most of the proposed ABE schemes for CCNNDN suffer from some loopholes. They are not flexible in the expression of access policy, they are inefficient, they are based on bilinear maps with pairings, and they are vulnerable to quantum cryptography algorithms. Hence, we propose the ciphertext policy attribute based encryption access control (CPABE AC) scheme from a lightweight ideal lattice based on ring learning with error (RLWE) problem, and demonstrated its use in practical applications. The proposed scheme is proved to be secure and efficient under the decision ring LWE problem in the selective set model. To achieve an efficient scheme, we used an efficient trapdoor technique and the access tree representation of access structure describing the access policies was modified into a new structure, based on a reduced ordered binary decision diagram (reduceOBDD). This access structure can support Boolean operations such as AND, NOT, OR, and threshold gates. The final result showed that the proposed scheme was secure and efficient for applications, thereby supporting CCNNDN as a promising paradigm.