Projects:2018s1-164 Private but Public on the Blockchain
Project Members
- Alexander Manariotis
- Jason Lu
Supervisors
- Dr Matthew Sorell
- Associate Professor Nickolas Falkner
Introduction
Blockchain technology utilises cryptography to sign transactions, with the public ledger consisting of cryptographically linked blocks [1]. Each block represents a transaction and collectively these blocks form a blockchain, i.e an untamperable record of transactions.
The implications of this technology are immense, as the need for a trusted third party to act as an intermediary is removed and ensures that only valid transactions are upheld (via public consensus) [1]. Ethereum extends the functionality of the blockchain beyond cryptocurrencies via smart contracts and decentralised applications, the former being an unalterable agreement that executes when a particular set of conditions have been fulfilled (all without the interference of a intermediary party) [2] and the latter being applications that utilise the Ethereum blockchain.
Despite the power of the blockchain and smart contracts, the present form of these technologies lacks transactional privacy [3]. Transactions propagate across the network, which publicly displays the addresses of the recipient and sender, the transaction amount and the smart contract data. This is not a feasible solution for private transactions and private data transmission as confidential data can be exploited. However, there are private cryptocurrencies like Zcash which facilitate private transactions via zero knowledge proofs [4]. Therefore as shown in Figure 1.0, there is gap in blockchain and privatisation technologies centred around Ethereum’s decentralised applications (otherwise known as Dapps).
Developers have been utilising external servers to achieve privacy, but this introduces a central entity which voids the key decentralisation of blockchain technology. “Permissioned” blockchains have also been utilised (where users are whitelisted), however the information is still available to all whitelisted users [5], making this unsuitable for business applications (as all employees would have to be trusted).
Therefore, through this research we hope to uncover the untapped potential of privatised blockchain technology and further the understanding of how this can be used in real-world applications.
