Cryptanalysis of a group key establishment protocol

In this paper, we analyze the security of a group key establishment scheme proposed by López-Ramos et al. This proposal aims at allowing a group of users to agree on a common key. We present several attacks against the security of the proposed protocol. In particular, an active attack is presented, and it is also proved that the protocol does not provide forward secrecy

The impact of the COVID-19 pandemic on grocery shopper behaviour: Analysis of shopper behaviour change using store transaction data

The systemic shock of coronavirus (COVID-19) and its impact on the global economy has been unprecedented with grocery shopper behaviour changing dramatically through various stages of the pandemic. COVID-19 has caused unusual market conditions, with significant changes to grocery shopper behaviour that need to be understood to allow for appreciation of shopperbehaviour change and retail planning implications during future systemic shocks. The aim of this study was therefore to understand grocery shopping behaviour during COVID19. Specific objectives were to investigate changes to grocery sale patterns by basket size, composition and category, as well as during specific time periods of the pandemic. The use of transaction data using a range of market basket indicators (e.g. value, size, product mix), revealed profound changes that indicate the challenge shoppers faced navigating a new ‘normal grocery shop’ and the pressure on retailers to analyse consumption changes inorder to prioritise demand planning. While the use of this data and analysis approach is an important contribution to consumer behaviour research, our focus was on the bigger patterns observed through the data pertaining to changes in shopper behaviour during systemic shocks.A key contribution of this paper is how the use of transaction data from grocery retail provides a nuanced understanding of how grocery shoppers responded leading up to and during the pandemic. For example, we found that grocery shoppers purchased more than just ‘daily staples’ to stock up during the pandemic, with increased awareness of health and wellbeing an important aspect

(<b><i>α, β</i></b>) - Lock Resolution Method of Linguistic Truth-Valued Intuitionistic Fuzzy First-order Logic

Automated reasoning is an important research direction in artificial intelligence, and resolution method is an efficient logical reasoning tool, it deserves to be studied. This paper establishes linguistic truth-valued intuitionistic fuzzy first-order logic (LTV-IFFL) system. To improve the resolution efficiency, the (αβ)-lock resolution method is introduced into LTV-IFFL system and requires that the resolution literal is the literal with the smallest lock number. Its soundness and completeness are proved. Finally, we give the (αβ) -locked resolution of the LTV-IFFL and apply it to the example.</p

Transparent Encryption for IoT using Offline Key Exchange over Public Blockchains

Internet of Things (IoTs) framework involves of a wide range of com- puting devices that rely on cloud storage for various applications. For instance, monitoring, analytics, surveillance and storing data for later processing within other applications. Due to compliance with security standards and trust issues with third- party cloud storage servers, the IoT data has to be encrypted before moving it to cloud server for storage. However, a major concern with uploading encrypted IoT data to cloud is the management of encryption keys and managing access policies to data. There are several techniques that can be used for storing cryptographic keys used for encryption/decryption of data. For instance, the keys can be stored with encrypted data on the cloud, a third-party key storage vault can be used for storing keys or the keys can stay with client so that they could download and decrypt the data by themselves. In case of encryption keys leakage, the data stored on the cloud storage could be compromised. To resolve the challenge of key management and secure access to data in third-party cloud storage, an end-to-end transparent encryp- tion model has been proposed that securely publishes the cryptographic keys in a blockchain ledger. The data is encrypted at edge gateway before it is transmitted to cloud for storage. The user does not require cryptographic keys to access data; a seamless process involves the client proving their identity to a crypto proxy agent built upon zero trust security principles, ensuring continuous verification