stampdio

This plugin allows you to stamp the contents of your posts to the blockchain. Protect the authenticity of your original work by timestamping the unique identifier (SHA256 hash) of each posts’s content.
Using this plugin you can stamp your posts and add a custom signature with the resulting hash and transaction ID.
Learn more about it and how it works: https://stampd.io/#/about
It requires that you have an account in stampd.io. Visit this URL to register: https://stampd.io/#/register

STAMPD.IO – Blockchain Stamping

This plugin allows you to stamp the contents of your posts to the blockchain. Protect the authenticity of your original work by timestamping the uniqu …

Copyscape

The Copyscape Premium plugin lets you check if a WordPress post is original before it’s published, by using the Copyscape Premium API to check for duplicate content on the web.
The plugin will add a ‘Copyscape Check’ button to your WordPress interface, allowing you to check your posts whenever you wish. You may also set the plugin to automatically check your posts when you click ‘Publish’ and/or ‘Update’.
When duplicate content is found, a report of matching pages is shown. You may also see a detailed comparison that highlights your content on the found page.
If you do not already have a Copyscape Premium account, please <a href="http://www.copyscape.com/redirect/?to=prosignup" title="Copyscape Premium sign up" rel="nofollow ugc">sign up</a>, <a href="http://www.copyscape.com/redirect/?to=propurchase" title="Purchase Copyscape Premium Credits" rel="nofollow ugc">purchase some credits</a>, and enable your <a href="http://www.copyscape.com/redirect/?to=apiconfigure#key" title="Copyscape Premium API page" rel="nofollow ugc">API access</a>. You may then begin using the plugin.

Copyscape Premium

The Copyscape Premium plugin lets you check if a WordPress post is unique before it's published, by searching for duplicate content on the web.

STAMPD.IO – Blockchain Stamping vs Copyscape Premium