A trustworthy source of randomness is a crucial component of many decentralized and crypto-based application systems, especially blockchain consensus. A decentralized random beacon (DRB) periodically outputs a new source of randomness generated using a distributed technique, such as publicly verifiable secret sharing (PVSS) or distributed verifiable random functions (VRFs). These protocols offer a variety of efficiency versus randomness quality tradeoffs, but guarantee security under a variety of configurations, assumptions, and adversarial models. This article aims to provide a future-proof unbiased decentralized randomness (abbreviated as Funder) via a post-quantum threshold VRF for sustainable proof-of-stake blockchain. We also provide a generic compiler for achieving post-quantum VRF from a classical VRF solution, but our approach makes use of symmetric-key primitives Our novel compiler is validated and evaluated using the ZKBoo and ZKB++ quantum-secure zero-knowledge systems, respectively. The implementation of the proof-of-concept demonstrates that the overheads introduced by our solution are acceptable for real-world deployments even in the present day. In addition, we demonstrate the protocol’s possible application in lottery-based proof-of-stake consensus protocols.

Decentralized control, low-complexity, flexible and efficient communications are the requirements of an architecture that aims to scale blockchains beyond the current state. Such properties are attainable by reducing ledger size and providing parallel operations in the blockchain. Sharding is one of the approaches that lower the burden of the nodes and enhance performance. However, the current solutions lack the features for resolving concurrency during cross-shard communications. With multiple participants belonging to different shards, handling concurrent operations is essential for optimal sharding. This issue becomes prominent due to the lack of architectural support and requires additional consensus for cross-shard communications. Relying on the advantages of hybrid Proof-of-Work/Proof-of-Stake (PoW/PoS), like Ethereum , hybrid consensus and 2-hop blockchain , we propose Reinshard , a new blockchain that inherits the properties of hybrid consensus for optimal sharding. Reinshard uses PoW and PoS chain-pairs with PoS sub-chains for all the valid chain-pairs where the hybrid consensus is attained through Verifiable Delay Function (VDF). Our architecture provides a secure method of arranging nodes in shards and resolves concurrency conflicts using the delay factor of VDF. The applicability of Reinshard is demonstrated through security and experimental evaluations. A practical concurrency problem is considered to show the efficacy of Reinshard in providing optimal sharding.

Critical infrastructure comprising on-demand devices, including secondary servers, comes into play when a situation like an overload is involved. The on-demand servers and devices require smart management solutions that form an integral part of Artificial Intelligence of Things (AIoT). This work considers AIoT as a combination of Mobile-Internet of Things (M-IoT) and AI requiring immediate response, secondary support system, and computational resources. Privacy in AIoT is always a concern when sharing information as intruders can eavesdrop on the settings of the system. This article uses an osmotic computing paradigm, which enables the derivation of strategies to decide on the methods of sharing services via optimal and privacy-aware resource management in AIoT. A safety competition is built on top of configuration rewards that help to attain privacy-by-design. The contributions of this article are expressed using theoretical analysis and numerical simulations.

Till now, the best defense against phishing is the use of two-factor authentication systems. Yet this protection is short-lived and comparatively weak. The absence of a fool-proof solution against man-in-the-middle, or active phishing, attacks have resulted in an avalanche of security practitioners painting bleak scenarios where active phishing attacks cripple the growth of Web-based transactional systems. Even with vigilant users and prudent applications, no solutions seem to have addressed the attacks comprehensively. In this article, we propose the new two-factor interlock authentication protocol (TIAP), adapted from the interlock protocol with two-factor authentication, which is able to defend successfully against active phishing attacks. We further scrutinize the TIAP by simulating a series of attacks against the protocol and demonstrate how each attack is defeated.