Block chain message service
The service described on this page is long dead and defunct.
- Message is kept inside the block-chain and it is therefore available forever.
- The message is copied to each existing bitcoin client in the world (currently order of 10^5 copies).
- A cryptographically signed timestamp as part of a bitcoin block serves as a proof that a message was written before that timestamp.
- Keeping the change left after message payment (the wallet private key) can be used as a proof for a message creation.
The protocol is open  , and open source tools for working with the protocol are available  . Reading such bitcoin messages can be done online  with the help of a Block_chain_browser, or offline  using a local copy of the block chain. Total anonymity is possible both for message readers and message writers, when the Anonymity guidelines are kept.
For writing a new message, the client creates an email request and gives instructions for a specific bitcoin payment transactions (address and fee). When the server gets the payment, it checks for the email request and processes the message. The server is a special customised bitcoin setup behind Tor.