- Whisper addresses are bitcoin addresses that are created using point addition by two or more people working together
- Only one of those people can withdraw money from the whisper address, and exchanges or governments can't know who it is
- Point addition works like this: take two or more public keys and add them together to get a new pubkey -- the whisper address
- The only way to get the whisper address's private key is to add together all the original private keys
- The money "senders" and the recipient create the whisper address, and the senders give their private keys to the money recipient
Super Testnet explaining why he made it
Whisper addresses are bitcoin addresses that are generated by means of point addition. Point addition will be described in a moment, first I want to share the "why."
Imagine you want to create a website to help protesters receive bitcoin in a country where protesting is illegal. You might create a spreadsheet that has the names of some of the protest leaders and their bitcoin addresses, then put that spreadsheet online so that people can find it easily and make their donations. One of the problems with that approach is that the donors aren't the only people who will see that page. The country's authorities could find the site too and order exchanges in their country to blacklist those addresses -- "if they try to cash out that bitcoin, confiscate it!"
This is where whisper addresses are helpful. Whisper addresses allow you to put something called a "linking key" into the field where a bitcoin address would go. Linking keys allow each visitor to your site to generate a bitcoin address that "belongs to" the person who created the linking key. Each visitor will generate a "whisper" bitcoin address which no one can associate with the linking key except the person who generated it and the recipient of the money. Each whisper address will start out empty. If the police visit the site, they will see an address that no one has ever seen before and which will likely never be seen again after the police leave the site. They can blacklist that address, but there's no money in it so it's no big deal. Each "legit" visitor will also generate a whisper address that belongs to the intended recipient. These whisper addresses will also be things that were never seen before, and therefore they are not on the police's blacklist. If the user sends money to it, they can also send some data to the intended recipient that allows them to find the address on the blockchain and withdraw the money in it to their regular wallet.
In short, the "why" of whisper addresses is censorship resistance. Whisper addresses are unique for each visitor to the site, cannot be associated with the recipient, and cannot be blacklisted by exchanges.
You can test out the new whisper addresses here on the main net.
Also see the bitcoin address here at the bottom of this page. You can pay that and we can use our Linking Key to get access to the Bitcoin you sent us using Whisper Address just make sure to send us whisper key via email.