4 ms·
In practice, checkpoint is not a big deal. For history older than X, where X is a sufficiently distant time in the past, there will always be widespread consens
by CryptoPunk 6y ago
In practice, checkpoint is not a big deal. For history older than X, where X is a sufficiently distant time in the past, there will always be widespread consensus on the hash of the true chain, and numerous reputable parties that the hash of the true chain can be obtained from. Some poison node attack where fraudulent websites provide a hash of a fake history will not be viable.
Checkpointing is also currently being utilized in Bitcoin Core, so relying on it further is not a major departure on how things are currently done.
And at 100X current block sizes, validating the entire history with no checkpoints will still be possible for thousands of hobbyists with beefed up but still modest hardware/bandwidth.
The empowerment from 100X more people being able to write transactions to the main chain, with their own private keys, will be well worth the relatively tolerable compromises on full node validation.
- tromp 6y agoBitcoin Core never did checkpointing in the sense of skipping prior history. They merely required a particular block at a particular height. Not fully verifying history is a complete departure from how things are done in bitcoin full nodes. And Bitcoin Core removed even those checkpoints [1]. [1] https://bitcoin.stackexchange.com/questions/75733/why-does-bitcoin-no-longer-have-checkpoints https://bitcoin.stackexchange.com/questions/75733/why-does-b...
- CryptoPunk 6y agoBitcoin Core removed that form of checkpointing, and added in another. Currently it has checkpointing in the form of assumevalid, which by default causes a full node to skip validation of transaction older than the checkpoint when synchronizing. [1] [1] https://bitcoin.stackexchange.com/questions/88652/does-assumevalid-lower-the-security-of-bitcoin https://bitcoin.stackexchange.com/questions/88652/does-assum...
- tromp 6y agoWell, that is depressing to learn. So by default, a bitcoin full node DOESN't fully validate transaction history. If it finds a particular block at a particular height (that a group of developers have signed off on), then all signature validations in prior blocks are assumed to be successful. The reasoning is that you have to trust those developers anyway not to sign off on malicious source code.
- CryptoPunk 6y agoYes, and that is why the alleged initial synchronization concerns surrounding larger blocks are mostly baseless. As it is, tens of millions of people can easily stream 700 KB/s HD video 24/7, yet Bitcoin is being kept to a throughput of 2 KB/s based on the claim that increasing it to satisfy market demand would lead to Bitcoin becoming centralized, with only large corporate entities left being able to fully validate. It's pure FUD.