new contract. If she loses her key, Bob will get the funds out eventually. If Bob turns out to
be malicious, then she can turn off his ability to withdraw.
2. Crop insurance. One can easily make a financial derivatives contract by using a data
feed of the weather instead of any price index. If a farmer in Iowa purchases a derivative
that pays out inversely based on the precipitation in Iowa, then if there is a drought, the
farmer will automatically receive money and if there is enough rain the farmer will be
happy because their crops would do well. This can be expanded to natural disaster
insurance generally.
3. A decentralized data feed. For financial contracts for difference, it may actually be
possible to decentralize the data feed via a protocol called SchellingCoin ↗ . SchellingCoin
basically works as follows: N parties all put into the system the value of a given datum (eg.
the ETH/USD price), the values are sorted, and everyone between the 25th and 75th
percentile gets one token as a reward. Everyone has the incentive to provide the answer
that everyone else will provide, and the only value that a large number of players can
realistically agree on is the obvious default: the truth. This creates a decentralized
protocol that can theoretically provide any number of values, including the ETH/USD price,
the temperature in Berlin or even the result of a particular hard computation.
4. Smart multisignature escrow. Bitcoin allows multisignature transaction contracts
where, for example, three out of a given five keys can spend the funds. Ethereum allows
for more granularity; for example, four out of five can spend everything, three out of five
can spend up to 10% per day, and two out of five can spend up to 0.5% per day.
Additionally, Ethereum multisig is asynchronous - two parties can register their signatures
on the blockchain at different times and the last signature will automatically send the
transaction.
5. Cloud computing. The EVM technology can also be used to create a verifiable
computing environment, allowing users to ask others to carry out computations and then
optionally ask for proofs that computations at certain randomly selected checkpoints were
done correctly. This allows for the creation of a cloud computing market where any user
can participate with their desktop, laptop or specialized server, and spot-checking
together with security deposits can be used to ensure that the system is trustworthy (ie.
nodes cannot profitably cheat). Although such a system may not be suitable for all tasks;
tasks that require a high level of inter-process communication, for example, cannot easily