Today, we are officially introducing a proof-of-work (PoW) defense for onion services designed to prioritize verified network traffic as a deterrent against denial of service (DoS) attacks with the release of Tor 0.4.8.
Either that or charging a micro transaction for loading the page. But yeah the goal is to make it cost a small amount that is insignificant to a regular user but adds up to a huge amount at the scale of a spam farm. And it’s also the same rationale behind hashing passwords with multiple rounds. It adds a tiny lag when you log in correctly but adds an insane amount of work if you’re checking every phrase in a password cracking dictionary using an offline attack because it adds up. (In the online scenario you just block them after a few attempts)
Either that or charging a micro transaction for loading the page. But yeah the goal is to make it cost a small amount that is insignificant to a regular user but adds up to a huge amount at the scale of a spam farm. And it’s also the same rationale behind hashing passwords with multiple rounds. It adds a tiny lag when you log in correctly but adds an insane amount of work if you’re checking every phrase in a password cracking dictionary using an offline attack because it adds up. (In the online scenario you just block them after a few attempts)