The Dawn of Trustworthy Computing
On the Internet, instead of securely and reliably handing over cash and getting our goods or services, or at least a ticket, we have to fill out forms and make ourselves vulnerable to identity theft in order to participate in e-commerce, and it often is very difficult to prohibitive to conduct many kinds of commerce, even purely online kinds, across borders and other trust boundaries. Today’s computers are not very trustworthy, but they are so astronomically faster than humans at so many important tasks that we use them heavily anyway. We reap the tremendous benefits of computers and public networks at large costs of identity fraud and other increasingly disastrous attacks.
Recently developed and developing technology, often called “the block chain”, is starting to change this. A block chain computer is a virtual computer, a computer in the cloud, shared across many traditional computers and protected by cryptography and consensus technology. A Turing-complete block chain with large state gives us this shared computer. Earlier efforts included state-machine replication (see list of papers linked below). QuixCoin is a recent and Ethereum is a current project that has implemented such a scheme. These block chain computers will allow us to put the most crucial parts of our online protocols on a far more reliable and secure footing, and make possible fiduciary interactions that we previously dared not do on a global network.
I had a similar thoughts when I discovered Bitcoin. It really is programmable money, in the sense that when you create a transaction, the transaction creates unspent coins associated with a small program for which you must find the right input values in order to spend them. The program is generally a digital signature validator, but you can craft something else within the limited opcodes of the Bitcoin protocol. Extend this a bit more and you get the capability to validate whatever you want and affect various states in the blockchain, which is what Ethereum did. We are entering the era of trustworthy distributed state machines.