Blockchains rely on a consensus among participants to achieve decentralization and security. However, reaching consensus in an online, digital world where identities are not tied to physical users is a challenging problem. Proof-of-work (PoW) provides a solution by linking representation to a...

The blockchain technology came to light in 2008 as a decentralised peer to peer network structure, with the ability to ensure security for transactions made on bitcoin cryptocurrency, without the need of any central server to validate transactions. Although it started with the advent of...

After creating a new blockchain transaction, the next step usually is to make miners aware of it by having it propagated through the blockchain's peer-to-peer network. We study an unintended alternative to peer-to-peer propagation: Exclusive mining. Exclusive mining is a type of collusion...

This paper studies to what extent the cost of operating a proof-of-work blockchain is intrinsically linked to the cost of preventing attacks, and to what extent the underlying digital ledger's security budgets are correlated with the cryptocurrency market outcomes. We theoretically derive an...

In the context of blockchain networks, mining describes a permissionless process intended to ensure the global consistency of a decentralised ledger. Mining requires the consumption of a costly computational resource to participate in a probabilistic competition that confers specific privileges...