<p>There is no serious usage, and has never been, of Hashcash. </p>

<p>Most obviously, the disparity between the resources of a spammer (who can rent a botnet of stolen compute resources, or use high powered servers and GPUs) is no match for a user sending an email from their phone with limited power available . This simply means that the difficulty of generating a "stamp" has to be so high that only spammers are able to send messages, which defeats the purpose. </p>

CC BY-SA 4.0
2018-12-28T07:03:50.397Z
2018-12-28T07:03:50.397Z
Claris
<p>I have been reading the <a href="http://www.hashcash.org/papers/hashcash.pdf" rel="nofollow noreferrer">Hashcash</a> paper which is referenced in the Bitcoin whitepaper. I would like to know what is the current state of the Hashcash protocol and what are the services that are actively using it?</p>

<whitepaper>
What is the current state of the Hashcash protocol that is cited in the Bitcoin whitepaper?
Abrar
# What is the current state of the Hashcash protocol that is cited in the Bitcoin whitepaper?

(Asked by: username_0 on 2018-12-28)

I have been reading the [Hashcash](http://www.hashcash.org/papers/hashcash.pdf) paper which is referenced in the Bitcoin whitepaper. I would like to know what is the current state of the Hashcash protocol and what are the services that are actively using it?

**Tags:** whitepaper


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## 1 answers

### Answer by username_1 on 2018-12-28. Score: 2 | Accepted answer

There is no serious usage, and has never been, of Hashcash.

Most obviously, the disparity between the resources of a spammer (who can rent a botnet of stolen compute resources, or use high powered servers and GPUs) is no match for a user sending an email from their phone with limited power available . This simply means that the difficulty of generating a "stamp" has to be so high that only spammers are able to send messages, which defeats the purpose.


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