TRR: TOR-inspired anonymity tool for Bitcoin
Tue 22 Sep 2015
Researchers at Shenzhen University, China, have introduced a new anonymity system for Bitcoin called Transaction Remote Release (TRR), inspired by the TOR network, to render typical deanonymising tools ineffective.
The technology uses multi-layered encryption to protect the identity of individuals carrying out Bitcoin transactions. However, unlike The Onion Router (TOR), TRR will not be available as a piece of software available for download. The Shenzhen team hope to integrate it directly into the Bitcoin network, providing a TRR-enabled setting which would offer layer encryption and trump current unmasking techniques.
These known deanonymising methods include Analysis of Transaction Chain (ATC) and Analysis of Bitcoin Protocol and Network (ABPN), which are able to deduce personal identities and source IP addresses from public blockchain data via weaknesses in Bitcoin anonymity. While several techniques have been developed to counter ATC attacks such as ZeroCoin and Coinjoin, there is no way of resisting ABPN attacks, apart from using TOR, which has proven unsafe and unreliable for Bitcoin transactions.
According to the paper, titled ‘Transaction Remote Release (TRR): A New Anonymization Technology for Bitcoin’, TRR is able to achieve faster connection speeds and greater stability than the TOR network, as it deals solely with Bitcoin transaction data. TRR will also be available globally, even across countries where TOR has been blocked. The researchers also argue that the TRR system is less vulnerable to middle-man attacks. While TOR exit nodes are prone to these attacks, there are no specific exit nodes in the Bitcoin network.
Despite these advantages, the paper highlights two drawbacks. Firstly, Bitcoin protocol would need to be amended to apply TRR, while TOR is already well-established in the Bitcoin community. Secondly, there is currently no way of identifying whether a client is trustworthy or not, so TRR could be vulnerable to fake requests and Denial of Service (DoS) attacks – an area which the team hopes to direct future research.