TCAM: Timebased content access control mechanism for ICN subscription systems Abstract   The demand for content usage over the Internet has exponentially increased with the rise in social networking, messaging, and smart devices. The hostcentric communication model was not primarily designed for content as its core element, rather it emphasis on the connection between hosts. InformationCentric Networking (ICN) is fast becoming an Internet architecture for content distribution. In ICN, content is located and retrieved dynamically from a source or a cache store, without any binding to the producer host machine. This ICN feature improves the network performances, however, it raises security concerns regarding user or consumer authorization and access control management for private contents. In addition, the privacy of data (and consumers) can be compromised since data are cached away from the producer. To overcome these security challenges, this work proposes a Timebased Content access control Mechanism for subscribed content (TCAM), which allows access only to authorized subscribers. The scheme allows the content producers to encrypt the content using their unique identities and defined accesstime. We utilize identitybased encryption, proxy reencryption, and broadcast encryption to ensure content dissemination and access management is done securely and effectively. Experimental and comprehensive security evaluation proves the effectiveness and reliability of the scheme.

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.