Research on Blockchain Security Threats
- During time-dilation attacks, an attacker controls the victim’s access to the Bitcoin network (hard, but not impossible) and delays block delivery to the victim.
- Attackers take advantage of the blockchain congestion and pair it with exploiting the HTLC deadlines.
- The attack relies on the bitcoin blockchain being filled to the brim with transactions so that no more can get through.
- The attacker hopes he or she can push the contracts past the built-in deadlines. If successful, the attacker can begin to "loot" the expired contracts.
- By attacking many channels and forcing them all to be closed at the same time [...], some of the victims’ HTLC-claiming transactions will not be confirmed in time, and the attacker will steal them.
- The novelty of this attack consists of delaying network communications between multiple subgroups of nodes with balanced mining power. It is due to the trade off between the network delay and the mining power of the attacker needed to double-spend in the GHOST protocol with high probability