Ethereum 2.0 Specifications

To learn more about sharding and Ethereum 2.0 (Serenity), see the sharding FAQ and the research compendium.

This repository hosts the current Eth2 specifications. Discussions about design rationale and proposed changes can be brought up and discussed as issues. Solidified, agreed-upon changes to the spec can be made through pull requests.

Specs

Core specifications for Eth2 clients be found in specs/. These are divided into phases. Each subsequent phase depends upon the prior. The current phases specified are:

Phase 0

• The Beacon Chain
• Fork Choice
• Deposit Contract
• Honest Validator
• P2P Networking

Phase 1

• From Phase 0 to Phase 1
• The Beacon Chain for Shards
• Custody Game
• Shard Transition and Fraud Proofs
• Light client syncing protocol

Phase 2

Phase 2 is still actively in R&D and does not yet have any formal specifications.

See the Eth2 Phase 2 Wiki for current progress, discussions, and definitions regarding this work.

Accompanying documents can be found in specs and include:

• SimpleSerialize (SSZ) spec
• Merkle proof formats
• General test format

Additional specifications for client implementers

Additional specifications and standards outside of requisite client functionality can be found in the following repos:

• Eth2 APIs
• Eth2 Metrics
• Interop Standards in Eth2 PM

Design goals

The following are the broad design goals for Ethereum 2.0:

• to minimize complexity, even at the cost of some losses in efficiency
• to remain live through major network partitions and when very large portions of nodes go offline
• to select all components such that they are either quantum secure or can be easily swapped out for quantum secure counterparts when available
• to utilize crypto and design techniques that allow for a large participation of validators in total and per unit time
• to allow for a typical consumer laptop with O(C) resources to process/validate O(1) shards (including any system level validation such as the beacon chain)

Useful external resources

• Design Rationale
• Phase 0 Onboarding Document
• Gasper paper

For spec contributors

Documentation on the different components used during spec writing can be found here:

• YAML Test Generators
• Executable Python Spec, with Py-tests