Secure your website from spammers and free-riders
Stop Bots and Earn Cash
Hashcash limits the amount of spam by solving math puzzles in visitor's browser,
secures your site against brute force attacks and scraping
(cash feature coming soon)
It is typical for "SEO Marketing Companies" to take advantage of forums and blogs by creating worthless posts and comments with links to a website they are promoting.
If your web-property allows user-generated content, you are likely to use CAPTCHA. CAPTCHAs are not perfect:
Today it is possible to buy access to an API which solves any CAPTCHA for just $0.70 per 1000 CAPTCHA images. And do you think your customer will be happy to try to solve one of these ridiculous CAPTCHAs?
Many modern web-applications are susceptible to brute force attacks.
Take a typical login form, for example. Hackers can compromise account security by trying every possible password combination. They can also leverage a large network of proxy servers to parallelize this attack.
Forcing their browser to work hard makes it too expensive and slow for hackers to perform a brute force attack.
We leverage the following technologies:
Browsers supported:
If you are using custom code or a framework/CMS which is not yet supported, you can use
jQuery.hashcash.io plugin for super simple integration.
Add jquery.hashcash.io.min.js into the <head> of your HTML page and call it
for the form which you would like to protect.
On a server side you need to make a single call to hashcash.io server to verify that the work was indeed done.
<html>
<head>
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<link type="text/css" rel="stylesheet" href="jquery.hashcash.io/jquery.hashcash.io.min.css" media="all" />
<script src="jquery.hashcash.io/jquery.hashcash.io.min.js"></script>
</head>
<body>
<form action="/addcomment" method="POST">
<textarea name="comment"></textarea><br />
<input type="submit" value="Submit Comment" />
</form>
<script>
$("form input[type=submit]").hashcash({
key: "YOUR-PUBLIC-KEY"
});
</script>
</body>
</html>if (! $_REQUEST['hashcashid']) {
die("Please unlock submit button.");
}
$url = 'https://hashcash.io/api/checkwork/' . $_REQUEST['hashcashid'] . '?apikey=[YOUR-PRIVATE-KEY]';
$work = json_decode(file_get_contents($url));
if (! $work) {
die("Please try again");
}
if ($work->verified) {
die("This proof-of-work was already used");
}
if ($work->totalDone < 0.01) {
die("You did not wait long enough");
}
saveAndPublishPost();# part of the standard Ruby library
require 'open-uri'
require 'json'
# denotes a HTTP route
post '/addcomment' do
id = params[:hashcashid]
privkey = "YOUR_PRIVATE_KEY"
if not id
return { :error => 'Please unlock submit button. }
end
url = "https://hashcash.io/api/checkwork/#{id}?apikey=#{privkey}"
# JSON will break if empty response.
begin
work = JSON.parse(open(url).read)
rescue Exception => e
return { :error => 'Something went wrong.' }
end
if work['verified']
return { :error => 'This proof-of-work was already used' }
end
if work['totalDone'] < 0.01
return { :error => 'You did not wait long enough.' }
end
do_your_thing
endCourtesy of Maxwell Bernstein
var express = require('express');
var bodyParser = require('body-parser');
var app = express();
var restler = require('restler');
var key = "[YOUR PRIVATE KEY]";
var complexity = 0.01;
var validateHashcash = function(req, res, next) {
var id = req.param('hashcashid');
restler.get(
'https://hashcash.io/api/checkwork/' + id,
{ query: { apikey: key }}
).on("success", function(data) {
if (data.verified) {
return res.json({ status: "error", message: "This proof-of-work was already used" });
}
else {
if (data.totalDone > complexity) {
return next();
}
else {
return res.json({ status: "error", message: "Not enough work done" });
}
}
}).on("fail", function() {
return res.json({ status: "error", message: "[fail] Proof of work not calculated" });
}).on("error", function() {
return res.json({ status: "error", message: "[error] Proof of work not calculated" });
});
};
var addcomment = function(req, res) {
return res.json({ status: "success", message: "comment posted" });
};
app.use(bodyParser());
app.post(
'/addcomment',
validateHashcash,
addcomment
);
app.listen(3000);