You can't fix 51% attacks on Bitcoin without adding centralization, argues core developer

The ability to 51% attack Bitcoin indicates that it's decentralized.

It's impossible to fix this vulnerability without adding centralization, argued Litecoin founder Charlie Lee and Bitcoin Core developer Gregory Maxwell.

Critics have scrutinized Bitcoin and other proof-of-work projects for their susceptibility to 51% attacks.

"One cannot fix the 51% attack flaw of a decentralized system without adding centralization," tweeted Litecoin creator Charlie Lee.

Bitcoin solves the double-spend problem by saying the first transaction to spend a coin is the valid transaction.

Gregory Maxwell, the former CTO of Blockstream and a longstanding Bitcoin Core developer, explains why.

If two transactions to spend the same Bitcoin happened at the same time, how would the network decide which is first and which is second?

Even though it's possible to make 51% attacks costlier or more inconvenient, it's impossible to eliminate that possibility without introducing centralization, argues Maxwell.

A transaction on the Bitcoin blockchain gets exponentially more difficult to compromise the more blocks are mined on top of it.

"A far bigger risk to Bitcoin is that the public using it won't understand, won't care, and won't protect the decentralization properties that make it valuable over centralized alternatives in the first place; a risk we can see playing out constantly in the billion dollar market caps of totally centralized systems," concluded Maxwell.