Decentralized verification of offchain computation

Various options for verification (in order of increasing decentralization) include:

1. Centralized Livepeer Verifier - API service that is run centrally and recomputes computation.

2. [Oraclize](http://oraclize.it) - Moving trust off of Livepeer onto a company that runs offchain computations as a business. They do work to provide proofs of execution if possible, and their reputation is tied up in their ability to do this verifiably.

3. Trusted Hardware - [Town Crier](town-crier.org), SGX, etc - Move trust off of a startup and onto the hardware implementation of Intel, Ledger, etc.

4. Custom majority rules schemes - have people execute the computation multiple times and report results. Trust majority and penalize majority, using stake as incentives.

5. [Truebit](http://truebit.io) - Formalized version of the above, consisting of verifiability on the blockchain.

The plan is to work with and move to Truebit as quickly as possible. This research track explores these options and others.

Start by comparing the five verification approaches listed in the issue, with particular attention to the stated plan to move to Truebit. Done means documenting the selected approach, its trade-offs, and concrete next steps for decentralized verification of offchain computation.

Written by the indexing model from the issue text.