this post was submitted on 19 Jun 2026
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Is it rewritable, or is it append only? You only wrote one sentence yet still managed to contradict yourself so I suspect you have a very meager comprehension of the technology.
As I understand, it's normally append-only. But, with some implementations, if a malicious entity controls most of the block production, they can undo recent transactions at will.
Some resort to majority vote, in the case of disagreements. Theoretically, if someone owned/controlled over 50% of the database, they could rewrite it, and have their version seen as true.
For the few valid uses of it, that shouldn't be a problem. It will also be reasonably detectable beforehand.
Go ahead and prove me wrong. Show me blockchain implementations that are immutable post append. On my end, we can talk about Bitcoin forks. We can also talk about the current state of consensus mechanisms, each of which has the explicit ability for large actors to rewrite history in their favor. Even Monero is susceptible because this is fundamental to the blockchain in any form. Itβs been a huge reason why I make sure I get paid up front for any consulting I do in this space.
Only the last few blocks are "rewritable," which is why a certain number of confirmations are a necessity. Going any further back than that, would be a completely different chain - a fork. The last of of those occurring on Bitcoin was thirteen years ago when it was still encountering growing pains due to an uptake in usage. Forks of more than a couple transactions are not a frequent, regular occurrence by any exaggeration, so for all intents and purposes of modern crypto usage,, it is immutable, not rewritable.