> When will it be uneconomical for an attacker to reorged these records out of the DaG? Depends on what hardware the attacker has available. A GPU offers at le

> When will it be uneconomical for an attacker to reorged these records out of the DaG? Depends on what hardware the attacker has available. A GPU offers at least an order of magnitude increase in efficiency over a CPU, while FPGAs and ASICs offer further orders of magnitude increases. The particular PoW used here (birthday collision) aims to be memory hard but falls to a sublinear memory-time tradeoff.