Reversecoin is the worlds first crypto-currency with "Reversible Transactions". Reversecoin proof-of-concept is based on Bitcoinpy. Final version of Reversecoin will be based on Bitcoin code, using Proof-of-Stake (PoS) for mining.
With Reversecoin, you can create two different kinds of accounts: Standard Accounts and Vault Accounts. Standard accounts behave very much like your Bitcoin accounts and allow you to send and receive money for daily purposes. Vault accounts behave much like you bank savings account, where you can deposit large amount of coins and keep them safe from hackers. Each vault account has a configurable timeout and is backed by two key pairs, one online and one offline. You only need online keypair to transfer coins from vault. When you transfer your coins using online keypair, your transactions get confirmed after they live in blockchain for the timeout period.
If someone steals your online key pair and transfers coins to them, the transactions will have to wait in block chain for the timeout period. During which, you can use your offline key pair and reverse those transactions and restore your coins to your other address. You can also use your offline key pair for immediate transfer of coins in your Vault, instead of waiting for timeout period. In a sentence, Vault account has the ease of use of hot wallets (online account) and security of cold wallets (offline accounts). We are also working on a monitoring service, to send you real-time alerts, when your coins are transferred from your addresses. To know more about Reversecoin, read our white paper or even better play with the vaultcoin, to see for yourself how Reversecoin works. In order to make it easy, the code is sandboxed and difficulty is reduced so that blocks are produced one every minute. Below is a brief tutorial to show how vaultcoin works.
In order to keep the code lightweight we built Reversecoin based on Bitcoinpy and reused the libraries including the Bitcoinlib by Jeff Garzik and others. Code contains all the components including the reversecoin server, client, wallet and miner. We will add support for missing functionality, albeit slowly. If you would like to contribute, please feel free to fork the project, hack it and send a pull request. We will gladly accept your changes. Any contributions including documentation are welcome.
To try out Reversecoin checkout out tutorial at: http://www.reversecoin.org/howitworks.html