Technology Overview

Erdstall is a Blockchain scaling solution using Trusted Execution Environments and is based on research results of the Chair of Applied Cryptography at the Technical University of Darmstadt, Germany.

Winner presentation from ETHOnline Hackathon

Architecture overview

Table of Contents

Users

Users can join the system by depositing funds into smart contracts and exit it by sending a message to the exit statement from the Erdstall system to the smart contract. They can send transactions to each other by sending them to the Operator. In regular intervals they receive balance proofs. 

Smart Contract

Users deposit their funds into the smart contract to join the Erdstall system. After the deposit, the contract holds the funds while they are processed off-chain. Smart contracts define how the funds are unlocked and the challenge-response logic in case of wrong behaviour of the users or the operator.

Operator

The Operator collects all transactions, blocks from users and forwards them to the TEE. After each transaction phase he receives balance proofs from the TEE and sends them back to the Users. It is important to know that the operator is not trusted! He can decide not to forward any information, but cannot forge messages or alter the state of the Erdstall system

TEE

The TEE runs the Erdstall Enclave which processes all transactions in the system. After each transaction phase it generates and sends balance proofs as well as exit proofs to users that want to leave the system.

Features of TEE

Secure Execution of Code

Computation result can't be change by outside influence

Private State

All computation and state is kept hidden from the operator

Attestation

Users can verify their transactions to the Plasma system

1. Deposit Phase (Requires on-chain transactions)

User funds the plasma contract

2. Transaction Phase

In this phase users can send transactions to each other. At the end of each transaction phase users get an updated and signed statement

3. Exit Phase (Requires on-chain transactions)

Users can exit the system and receive signed exit statements

Epoch

Erdstall proceeds in Epochs to enable transcations