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It doesn't have "blocks" in any meaningful sense, though, largely because it doesn't have mining, because it has no double-spend problem. If two certs get issue

by geofft 5y ago

It doesn't have "blocks" in any meaningful sense, though, largely because it doesn't have mining, because it has no double-spend problem. If two certs get issued for the same site, they're both valid and you want to record them both. CT is my favorite example of why you probably don't need a blockchain for most permissionless distributed-ledger applications. If you're not making a currency, you probably don't have a double-spend problem at all. For instance, the decentralized package integrity system for Go is based on CT, not blockchains. The benefit of not having blocks or mining is that the transaction costs are basically zero in both time and energy. One person is running a CT log in their home, and it works as well as any of the logs run by big companies. This is both a practical operational advantage and a way to avoid complaints about harming the planet. (The big non-currency use case where there is a double-spend problem is timestamping. Here, the two histories of which only one can be true are "This event didn't happen today" and "This event happened today." Blockchains solve this straightforwardly, but you can still address it in a CT-style system - the whole "precertificate" setup is essentially a restricted form of timestamping.)

tialaramex 5y ago
> One person is running a CT log in their home, and it works as well as any of the logs run by big companies But presumably not a publicly trusted CT log as that seems like a recipe for disaster? The public CT logs are obliged to achieve 24 hours MMD (Maximum Merge Delay). If, for any reason, you aren't able to publish a new log incorporating certificates you signed SCTs for within 24 hours, your log is distrusted. Obviously it's trivial to hit 24 hours MMD when everything works. You could probably do it in Visual BASIC for Excel for low volumes, no trouble. But, there are no exceptions, so you need to have epic disaster recovery otherwise when anything goes wrong and you can't fix it until tomorrow it's game over because you missed the 24 hour deadline.

by geofft 5y ago

tialaramex 5y ago

> One person is running a CT log in their home, and it works as well as any of the logs run by big companies But presumably not a publicly trusted CT log as that seems like a recipe for disaster? The public CT logs are obliged to achieve 24 hours MMD (Maximum Merge Delay). If, for any reason, you aren't able to publish a new log incorporating certificates you signed SCTs for within 24 hours, your log is distrusted. Obviously it's trivial to hit 24 hours MMD when everything works. You could probably do it in Visual BASIC for Excel for low volumes, no trouble. But, there are no exceptions, so you need to have epic disaster recovery otherwise when anything goes wrong and you can't fix it until tomorrow it's game over because you missed the 24 hour deadline.