Abstract Mobile edge computing (MEC) technology is widely used for real‐time and bandwidth‐intensive services, but its underlying heterogeneous architecture may lead to a variety of security and privacy issues. Blockchain provides novel solutions for data security and privacy protection in MEC. However, the scalability of traditional blockchain is difficult to meet the requirements of real‐time data processing, and the consensus mechanism is not suitable for resource‐constrained devices. Moreover, the access control of MEC data needs to be further improved. Given the above problems, a data privacy protection model based on sharding blockchain and access control is designed in this paper. First, a privacy‐preserving platform based on a sharding blockchain is designed. Reputation calculation and improved Proof‐of‐Work (PoW) consensus mechanism are proposed to accommodate resource‐constrained edge devices. The incentive mechanism with rewards and punishments is designed to constrain node behavior. A reward allocation algorithm is proposed to encourage nodes to actively contribute to obtaining more rewards. Second, an access control strategy using ciphertext policy attribute‐based encryption (CP‐ABE) and RSA is designed. A smart contract is deployed to implement the automatic access control function. The InterPlanetary File System is introduced to alleviate the blockchain storage burden. Finally, we analyze the security of the proposed privacy protection model and statistics of the GAS consumed by the access control policy. The experimental results show that the proposed data privacy protection model achieves fine‐grained control of access rights, and has higher throughput and security than traditional blockchain.

The casting service on SmartTV has been increasingly used for home entertainment and business, given the convenience offered in media broadcast and screen sharing. Among the underlying protocols that support TV cast, DLNA (Digital Living Networking Alliance) – established by a group of tech giants – has become a prevailing standard in the consumer market. Although DLNA has launched the market for years, concerns may arise about whether its real-world deployment has been clearly understood.In this work, we systematically evaluate the security of DLNA deployments in the SmartTV ecosystem. Specifically, we identify a series of critical security issues in the interactions between SmartTVs and casting apps on the smartphone, ranging from non-mandatory encryption to unauthorized file access. The identified security risks can be exploited by a malicious app on the victim’s phone, without requesting sensitive permissions, to launch multiple attacks, including arbitrary command execution, data theft, MITM (man-in-the-middle) attack, and DoS (denial-of-service) attack. To measure the impact of the identified security issues, we designed semi-automated analysis solutions to facilitate the measurements and conducted real-world experiments on 10 on-shelf TV boxes. The results show that most DLNA implementations of products and apps in the wild are insecure. In the end, we provide immediate improvement solutions to mitigate the identified security issues.