Long-Range Attacks

Long-range attacks occur when an adversary creates an alternative chain starting from a point far back in the blockchain history, potentially even from the genesis block. By gaining control of enough private keys or historical validator sets, the attacker can produce a chain that looks valid to new nodes joining the network.

This is particularly dangerous for proof-of-stake systems where historical validator sets may no longer be active or reachable. If a node cannot distinguish the legitimate chain from the attacker's chain, it may accept the malicious version as the source of truth.

This could lead to the invalidation of significant financial transactions that occurred before the attacker started the fork. Protecting against these attacks often requires checkpoints or social consensus, where the community agrees on the canonical history.

In derivatives, such an attack could lead to the catastrophic loss of funds if the attacker manages to double-spend collateral across the fake chain.