Add basic README.md

README.md

@@ -1 +1,32 @@
 # eth-attestor
+
+Scalable on-chain trustless attestations to data from any past Ethereum block or state.
+
+## Project overview
+
+This repository provides implementations of account, storage, and transaction proofs for
+Ethereum.  Together, these enable a user to generate validity proofs for data from any
+current or past Ethereum block or state using a trusted block hash alone.
+
+## Install dependencies
+
+* Run `yarn` at the top level to install npm dependencies (`snarkjs` and `circomlib`).
+* You'll also need `circom` version >= 2.0.2 on your system. Installation instructions [here](https://docs.circom.io/getting-started/installation).
+* Building these circuits requires a Powers of Tau file with `2^24` constraints in the `circuits` subdirectory with the name `pot24_final.ptau`. One such file can be downloaded from the Hermez trusted setup [here](https://github.com/iden3/snarkjs#7-prepare-phase-2).
+
+## Building proving keys and witness generation files
+
+We provide four circuits, which together enable attestations to all current or
+historical Ethereum data available from an archive node:
+
+* `eth_block_hash`: Prove state, transaction, and receipt roots corresponding to a block hash.
+* `address_proof`: Prove an account state corresponding to a state root.
+* `storage_proof`: Prove the contents of a storage slot with corresponding storage root.
+* `tx_proof`: Prove the contents of a transaction with corresponding transaction root.
+
+Run `yarn build:eth_block_hash`, `yarn build:address`, `yarn build:storage`, `yarn build:tx` at the
+top level to compile proving keys and witness generators for each file.
+
+## Testing
+
+Run `yarn test` at the top level to run tests. Note that these tests only test correctness of witness generation.