Cyberattacks

While in theory Blockchains are vulnerable to cyberattacks including Sybil 51per cent attacks and distributed denial of service, the combination of decentralized database architecture, cryptography and the principles of immutability and consensus make Blockchain-based distributed ledgers relatively resilient to cyber-attacks (see section 2for further explanations). The types of attacks that a Blockchain is susceptible to depend upon a range of characteristics. For example, Blockchains with fewer nodes are at a greater risk for 51per cent attacks, while permission less Blockchains may be more at risk of identity theft than permissioned Blockchains where access is more restricted. Another vulnerability that will probably arise in the future is the development of quantum-speed computers, and their possible use for hacking, given the extensive reliance of Blockchains on cryptographic techniques.