In order to solve the problems of copyrights infringement, high cost and complex process of rights protection in current media convergence center, a digital rights management system based on blockchain technology and IPFS (Inter Planetary File System) technology is proposed. Considering that large files such as video and audio cannot be stored on the blockchain directly, IPFS technology is adopted as the data expansion scheme for the data storage layer of the Ethereum platform, IPFS protocol is further used for distributed data storage and transmission of media content. In addition, smart contract is also used to uniquely identify digital rights through NFT (Non-fungible Tokens), which provides the characteristics of digital rights transferability and traceability, and realizes an open, transparent, tamper-proof and traceable digital rights management system for media convergence center. Several experimental results show that it has higher transaction success rate, lower storage consumption and transaction confirmation delay than existing scheme.

Bitcoin is one of popular cryptocurrencies widely used over the world, and its blockchain technology has attracted considerable attention. In Bitcoin system, it has been reported that transactions are prioritized according to transaction fees, and that transactions with high priorities are likely to be confirmed faster than those with low priorities. In this paper, we consider performance modeling of Bitcoin-blockchain system in order to characterize the transaction-confirmation time. We first introduce the Bitcoin system, focusing on proof-of-work, the consensus mechanism of Bitcoin blockchain. Then, we show some queueing models and its analytical results, discussing the implications and insights obtained from the queueing models.

This letter presents the safety confirmation system based on Near Field Communication (NFC) and Ultra High Frequency (UHF) band Radio Frequency IDentification (RFID) tags. Because these RFID tags can operate without the need for internal batteries, the proposed safety confirmation system is effective during large-scale disasters that cause loss of electricity and communication infrastructures. Sharing safety confirmation data between the NFC and UHF band RFID tags was studied to confirm the feasibility of the data sharing. The prototype of the proposed system was fabricated, confirming the feasibility of the proposed safety confirmation system.

A group key exchange (GKE) protocol allows a group of parties communicating over a public network to establish a common secret key. As group-oriented applications gain popularity over the Internet, a number of GKE protocols have been suggested to provide those applications with a secure multicast channel. In this work, we investigate the security of Wu and Zhu's password-authenticated GKE protocol presented recently in FC'08. Wu and Zhu's protocol is efficient, supports dynamic groups, and can be constructed generically from any password-authenticated 2-party key exchange protocol. However, despite its attractive features, the Wu-Zhu protocol should not be adopted in its present form. Due to a flaw in its design, the Wu-Zhu protocol fails to achieve authenticated key exchange. We here report this security problem with the Wu-Zhu protocol and show how to solve it.

This article shows a Boolean Multivalued logical model of varying confirmation by observation of events in human inference and, as an introductory example, applies the model to solve Hempel's paradox of the ravens.