Author: Alejandro Ranchal Pedrosa 2019-04-16 00:14:59
Published on: 2019-04-16T00:14:59+00:00
The email discusses the construction of channel factories and the splice-out mechanism that claims to solve a stale factory situation. The writer explains why this mechanism can be easily attacked in what is called the Broken Factory attack. The scenario presented is a factory created between Alice, Bob, Carol, and Dave with channels F_AC, F_AB, F_BC, and F_CD. Suppose Dave cannot update the channel factory; the splice-out mechanism should allow them to do so by redirecting outputs of the channels of the factory to a new factory. However, after creating the new hook, Alice and Bob can update their former channel state and invalidate the state R1_AB, making it older than a new state R2_AB, which invalidates one of the inputs of the new Hook H_ABC, thus proving that the splice-out mechanism is not possible without a race condition.
Updated on: 2023-06-02T18:22:13.181791+00:00