Ask HN: Are small blockchains secure?

2 pointsbenp848y ago2 comments

I finally read the Bitcoin white paper and there's one thing I don't get. The security relies on the majority of miners agreeing on the state of the global ledger, where "the majority" is measured in computing power.

It seems reasonable to assume that the computing power of a malicious miner doesn't stand a chance against the enormous hashing power currently devoted to Bitcoin, but what about smaller blockchains? Couldn't the biggest Bitcoin miner just switch all their resources to Litecoin for a few minutes and cause complete havoc? I imagine the smallest blockchains could be hacked/ruined just by someone with a fairly high AWS Lambda rate limit.

I keep hearing about new projects to use blockchains for every little thing, and I just can't imagine how any blockchain other than the big one can be secure.

2 comments

2 comments · 1 top-level

wmf8y ago· 1 in thread

Couldn't the biggest Bitcoin miner just switch all their resources to Litecoin for a few minutes and cause complete havoc?

That particular case is not possible because Bitcoin and Litecoin require different equipment to mine, so Bitcoin miners literally cannot mine Litecoin at any speed. But when two different blockchains use the same mining equipment it is possible for miners to switch chains at any time and thus a large miner could perform a 51% attack against a small chain. So small blockchains are not secure.

new projects to use blockchains for every little thing

Most of these projects would be better off running on top of an existing blockchain like Ethereum to avoid this problem.

benp84OP8y ago

Thank you! That makes a lot of sense.

j / k navigate · click thread line to collapse