description: A curated reader on Ethereum 2.0 technology
# Ethereum 2.0 Info
This page is unmaintained and the information is now quite out of date.
The best current resource I can recommend is my **[Upgrading Ethereum](https://eth2book.info/latest/)** book.
Canonical link: https://eth2.info
Here are what I consider to be quality sources of information for those wanting to build a strong understanding of Ethereum 2.0. Technical depth increases as you work down the page.
Things have evolved rapidly over the last year, and information may have become out of date. I've noted freshness dates for most things: the older they are the more cautious one ought to be. For the freshest week-by-week updates, see [What's new in Eth2](https://eth2.news).
This list is not aiming to be comprehensive: kind of the opposite; I'm aiming to cut down on the noise. If you have a resource you feel should be added, send me a note at `firstname.lastname@example.org` and I'll consider it. But no promises.
_Note that the [Ethereum 2.0 Devs Handbook and FAQs](https://notes.ethereum.org/@serenity/handbook) has had a major refresh after lying fallow for a while. It covers much the same ground, so take a look at that as well._
A good single article overview is this super-accessible but not dumbed down [article from bitrates](https://www.bitrates.com/news/p/examining-ethereum-20-this-is-not-your-grannys-blockchain) (August 2019). A little more up-to-date and in-depth is [ETH2 for Dummies](https://medium.com/@chromaticcapital/eth2-for-dummies-11ff9b11509f) from Chromatic Capital (January 2020).
EthHub has a nicely structured [overview of Ethereum 2.0](https://docs.ethhub.io/ethereum-roadmap/ethereum-2.0/sharding/) (July 2019) <!-- https://github.com/ethhub-io/ethhub/tree/master/docs/ethereum-roadmap/ethereum-2.0 -->
From Carl Beekhuizen on the Ethereum Foundation blog:
- [Validated: Staking on eth2 #0](https://blog.ethereum.org/2019/11/27/Validated-Staking-on-eth2-0/): a very accessible over view of the Ethereum 2.0 phases, the actors in the system and the design philosophy. (November 2019)
- [Validated, staking on eth2: #1 - Incentives](https://blog.ethereum.org/2020/01/13/validated-staking-on-eth2-1-incentives/): What are rewards, penalties and slashings, and why do we have them? (January 2020)
- [Validated, staking on eth2: #2 - Two ghosts in a trench coat](https://blog.ethereum.org/2020/02/12/validated-staking-on-eth2-2-two-ghosts-in-a-trench-coat/). This gets a little more technical, and discusses the consensus mechanisms in Eth2. (February 2020)
- [Validated, staking on eth2: #3 - Sharding Consensus](https://blog.ethereum.org/2020/03/27/sharding-consensus/): why we organise validators into committees and how we keep those committees secure. (March 2020)
Next up, some of my own articles 😂 These are not very technical and give an overview of history and progress for the more general audience.
- [Ethereum 2.0 introduction](https://media.consensys.net/state-of-ethereum-protocol-1-d3211dd0f6) (August 2018)
- [The Beacon Chain](https://media.consensys.net/state-of-ethereum-protocol-2-the-beacon-chain-c6b6a9a69129) (October 2018)
- [Exploring Ethereum 2.0 Design Goals](https://media.consensys.net/exploring-the-ethereum-2-0-design-goals-fd2d901b4c01) (January 2019)
- [Welcome to the Bazaar](https://media.consensys.net/ethereum-2-0s-latest-strides-forward-13f63652e57d) (July 2019)
- [Interoperability Workshop Review](https://media.consensys.net/how-30-eth-2-0-devs-locked-themselves-in-to-achieve-interoperability-175e4a807d92) (September 2019)
A helpful [glossary of Eth2 terms](https://medium.com/alethio/ethereum-2-0-terms-demystified-8398357429d7) from Alexandru Tudorache (August 2019)
Colin Schwartz of Chainsafe is working on a "complete guide" to Ethereum 2.0:
- [Ethereum 2.0: A Complete Guide](https://medium.com/chainsafe-systems/ethereum-2-0-a-complete-guide-d46d8ac914ce) (June 2019)
- [Scaling, Part One](https://medium.com/chainsafe-systems/ethereum-2-0-a-complete-guide-3739a74be61a) (June 2019)
- [Scaling Ethereum — Part Two: Sharding](https://medium.com/chainsafe-systems/ethereum-2-0-a-complete-guide-scaling-ethereum-part-two-sharding-902370ac3be) (July 2019)
- [Casper and the Beacon Chain](https://medium.com/chainsafe-systems/ethereum-2-0-a-complete-guide-casper-and-the-beacon-chain-be95129fc6c1) (August 2019)
Equally, Status is building a "Two Point Oh" [series](https://our.status.im/tag/two-point-oh/):
- [Explaining Validators](https://our.status.im/two-point-oh-explaining-validators/) (November 2018)
- [The Beacon Chain](https://our.status.im/two-point-oh-the-beacon-chain/) (November 2018)
- [The Tale of Two Ethers](https://our.status.im/two-point-oh-the-tale-of-two-ethers/) (November 2018)
- [Randomness](https://our.status.im/two-point-oh-randomness/) (May 2019)
- [9 Things You Didn't Know About Ethereum 2.0](https://our.status.im/9-things-you-didnt-know-about-ethereum-2-0/) (July 2019)
- [Justification and Finalization](https://our.status.im/two-point-oh-justification-and-finalization/) (August 2019)
My top introductory picks for listening and watching:
- Danny Ryan's [Eth 2.0 tldr](https://slideslive.com/38919931/eth-20-tldr) presentation from DevCon V (October 2019)
- [Vitalik at Deconomy](https://www.youtube.com/watch?v=izzMuxD4OAM) (May 2019)
- Hsiao-Wei Wang's "Life of An Ethereum Beacon Chain Validator": [video](https://www.youtube.com/watch?v=P4loHGCplX4), beautiful [slides](https://docs.google.com/presentation/d/1JlQ8fVZUvt7ywRcI7mj1ExmPxcNII2xKT4lkgnkq7gU/edit#slide=id.g52948b393d_2_75) (April 2019)
- Danny Ryan's [ZeroKnowledge podcast](https://www.zeroknowledge.fm/66) (February 2019)
- Justin Drake's [Epicenter podcast](https://epicenter.tv/episode/263/) (November 2018) This is well worth 70 minutes of your listening time. There's also a transcript there
- Robert Drost summarises Eth2 Phase 2 design: [video](https://www.youtube.com/watch?v=gHWMEmM940o), [slides](https://drive.google.com/file/d/1ufvspealOGje6GPp-yJnCeO73bch1wRe/edit) (July 2019)
If you want a single-article overview from a technical point of view, James Prestwich's [What to Expect When ETH’s Expecting](https://hackernoon.com/what-to-expect-when-eths-expecting-80cb4951afcd) (January 2019) hits the high points.
The [Sharding FAQ](https://github.com/ethereum/wiki/wiki/Sharding-FAQ) (April 2019) and the [Proof of Stake FAQ](https://github.com/ethereum/wiki/wiki/Proof-of-Stake-FAQ) (August 2019) remain excellent resources on the key innovations of Ethereum 2.0 vs 1.0. They are great places to learn the key concepts and terminology.
The [specification repo](https://github.com/ethereum/eth2.0-specs) is the canonical source of information. But the specs themselves are dense, and really belong under the _Intense_ heading. My [annotated specifications](https://benjaminion.xyz/eth2-annotated-spec) may be more accessible.
The following articles help to get under the skin of the spec to understand what's really going on:
- [Serenity Design Rationale](https://notes.ethereum.org/9l707paQQEeI-GPzVK02lA?view#) (August 2019) How Vitalik sees things.
- Phase 0 proof of stake
- [Phase 0 for Humans](https://notes.ethereum.org/@djrtwo/Bkn3zpwxB?type=view) (January 2020) This provides a more narrative complement to the explanation-lite [Phase 0 spec](https://github.com/ethereum/eth2.0-specs/blob/master/specs/core/0_beacon-chain.md).
- [Phase 0 -- Honest Validator](https://github.com/ethereum/eth2.0-specs/blob/dev/specs/validator/0_beacon-chain-validator.md) (July 2019) One of the best ways to understand the spec is to understand how validators are expected to behave.
- [A Validator’s Journey Through the Beacon Chain](https://medium.com/alethio/ethereum-2-a-validators-journey-through-the-beacon-chain-843f70aaab2e) (February 2020)
- A very thorough explanation of [Rewards and Penalties](https://codefi.consensys.net/blog/rewards-and-penalties-on-ethereum-20-phase-0) by ConsenSys Codefi (March 2020)
- Some nice explainers around the staking process from Jim McDonald,
- [Understanding validator effective balance](https://www.attestant.io/posts/understanding-validator-effective-balance/) (November 2019)
- [Understanding Ethereum staking deposits](https://www.attestant.io/posts/understanding-ethereum-staking-deposits/) (December 2019)
- [Exploring Staking Keys](https://www.attestant.io/posts/exploring-staking-keys/) (December 2019)
- [Exploring Ethereum 2 Validator Costs](https://www.attestant.io/posts/exploring-ethereum-2-validator-costs/) (January 2020)
- [Understanding the validator lifecycle](https://www.attestant.io/posts/understanding-the-validator-lifecycle/) (January 2020)
- [Explaining the Liveness Guarantee](https://ethresear.ch/t/explaining-the-liveness-guarantee/4228), aka the quadratic leak (November 2018)
- A nice, concise [Casper FFG Explainer](https://www.adiasg.me/2020/03/31/casper-ffg-explainer.html) from Aditya Asgaonkar (March 2020), and another on [How Casper FFG is implemented in Eth2.0](https://www.adiasg.me/2020/04/09/casper-ffg-in-eth2-0.html) (April 2020)
- [What is Simple Serialize (SSZ)](https://ethereum.stackexchange.com/questions/74005/what-is-ssz-simpleserialize-and-why-was-it-developed), from Ethereum StackExchange: a great answer from Paul Hauner (April 2020)
- Phase 1 sharding
- The [new sharding design](https://notes.ethereum.org/KbEyHiaSRQW_KS7dDK0OFw) (October 2019)
- Phase 2 execution environments
- [Ethereum 2.0 Phase 2 Progress](https://email@example.com/ethereum-2-0-phase-2-progress-7673b57eabff) (November 2019)
- [Eth2 Phase 2 WIKI](https://hackmd.io/UzysWse1Th240HELswKqVA) (August 2019)
- Danny Ryan's [Chain Reaction](https://podcasts.apple.com/us/podcast/ethereums-danny-ryan-the-definitive-eth-2-0-update/id1438148082?i=1000456505887) podcast nicely covers recent changes to Phase 1 shard chains (November 2019)
- Will Villanueva [discusses Phase 2](https://ethhub.substack.com/p/will-villanueva-ethereum-20-phase) on Into the Ether (November 2019)
- Justin Drake's [Whiteboard session](https://www.youtube.com/watch?v=S262StTwkmo) (February 2019) with NEAR protocol
- Vitalik on [The Phase 2 Design Space](https://www.youtube.com/watch?v=RW7K3JQOZOg&t=2089) (June 2019) (It's 40 minutes, but keep watching for more good stuff that follows.)
Visual thinkers will appreciate [Protolambda's diagrams](https://github.com/protolambda/eth2-docs) (July 2019)
The following are deep dives into specific aspects of the Eth2 protocols. For an attempt at a comprehensive deep-dive, take a look at my [Eth2 Annotated Specification](https://benjaminion.xyz/eth2-annotated-spec) (work in progress, February 2020).
- Phase 0
- The [Phase 0 Deep Dive](https://docs.google.com/presentation/d/1MZ-E6TVwomt4rqz-P2Bd_X3DFUW9fWDQkxUP_QJhkyw/edit#slide=id.g621e2d5823_0_205) from DevCon V is a good starting point. Here's [video](https://slideslive.com/38920088/eth2-phase-0-technical-deep-dive) from the 2 hour session (October 2019). It covers:
- [Casper FFG](https://docs.google.com/presentation/d/1MZ-E6TVwomt4rqz-P2Bd_X3DFUW9fWDQkxUP_QJhkyw/edit#slide=id.g620ddc5326_0_307) consensus
- [LMD GHOST](https://docs.google.com/presentation/d/1MZ-E6TVwomt4rqz-P2Bd_X3DFUW9fWDQkxUP_QJhkyw/edit#slide=id.g621e1673fb_1_47) fork choice
- [BLS signatures](https://docs.google.com/presentation/d/1MZ-E6TVwomt4rqz-P2Bd_X3DFUW9fWDQkxUP_QJhkyw/edit#slide=id.g621e1673fb_21_138) and aggregation
- [Validator lifecycle](https://docs.google.com/presentation/d/1MZ-E6TVwomt4rqz-P2Bd_X3DFUW9fWDQkxUP_QJhkyw/edit#slide=id.g621e1673fb_11_75)
- Beacon chain [state transition](https://docs.google.com/presentation/d/1MZ-E6TVwomt4rqz-P2Bd_X3DFUW9fWDQkxUP_QJhkyw/edit#slide=id.g621e1673fb_6_58)
- [Validator duties](https://docs.google.com/presentation/d/1MZ-E6TVwomt4rqz-P2Bd_X3DFUW9fWDQkxUP_QJhkyw/edit#slide=id.g621d74a5e7_0_216)
- [Phase 0 design notes](https://notes.ethereum.org/@JustinDrake/rkPjB1_xr) from Justin Drake (January 2020)
- [A note on Ethereum 2.0 phase 0 validator lifecycle](https://notes.ethereum.org/@hww/lifecycle), Hsiao-Wei Wang’s write up of the details (February 2020)
- BLS signatures
- [BLS12-381 for the Rest of Us](https://hackmd.io/@benjaminion/H1lkISO3JU) - everything you could possible want to know, without too much mathematical baggage. (January 2020)
- [BLS Signature aggregation](https://ethresear.ch/t/pragmatic-signature-aggregation-with-bls/2105) in Eth2 (May 2018)
- Herman Junge's [BLS for busy people](https://gist.github.com/hermanjunge/3308fbd3627033fc8d8ca0dd50809844) (November 2019)
- The [Design Decision Rationale](https://github.com/ethereum/eth2.0-specs/blob/dev/specs/networking/p2p-interface.md#design-decision-rationale) in the networking specification is insightful reading.
- How validators vote to [agree on their view of the Eth1 chain](https://hackmd.io/@prestonvanloon/H1rfsG5iH), for onboarding new validators (November 2019)
- SSZ ("simple" serialize)
- Protolambda's [SSZ documentation](https://github.com/protolambda/eth2.0-ssz) (November 2019)
- Video [explainer of SSZ](https://drive.google.com/file/d/1BUyokWe7y_qZcBT8vxhD4nzJiZwX8IgY/view) with Matt Garnett (November 2019)
- [Merkle tree type abstraction](https://github.com/protolambda/eth-merkle-trees/blob/master/typing_partials.md) (December 2019)
- How to [detect slashing conditions](https://hackmd.io/@sYlY_LZpQIGgFmhdv6vV-A/By897a5sH) (November 2019). The [background](https://github.com/ethereum/eth2.0-pm/issues/63).
- Weak subjectivity
- Early Vitalik blog post [explaining Weak Subjectivity](https://blog.ethereum.org/2014/11/25/proof-stake-learned-love-weak-subjectivity/) (November 2014)
- An [explainer](https://www.symphonious.net/2019/11/27/exploring-ethereum-2-weak-subjectivity-period/) from Adrian Sutton (November 2019)
- [Weak subjectivity under the exit queue model](https://ethresear.ch/t/weak-subjectivity-under-the-exit-queue-model/5187?u=benjaminion) (March 2019)
- Phase 1
- Proof of custody: Dmitry Khovratovich audited the original proof of custody design for Phase 1. He proposes an [updated construction](https://github.com/ethereum/eth2.0-specs/files/3551615/legendre_proof_of_custody_uhf.pdf) (August 2019), which has a nice introduction to the problem. The [audit report](https://github.com/ethereum/eth2.0-specs/files/3537084/Legendre.7.pdf) is insightful.
- [Data availability](https://medium.com/swlh/data-availability-on-ethereum-2-0-light-node-en-aec1ce6ac17c) (November 2019)
- Phase 2
- [Atomic cross shard communication](https://ethresear.ch/t/commit-capabilities-atomic-cross-shard-communication/6509?u=benjaminion) (November 2019)
- [Relay Networks and Fee Markets in Eth 2.0](https://medium.com/@adlerjohn/relay-networks-and-fee-markets-in-eth-2-0-878e576f980b) (November 2019)
- Notes on [Execution Toolchain for Ethereum 2.0](https://github.com/quilt/pm/issues/2) (November 2019)
- [Ewasm 2.0: State Execution in Eth 2.0](https://www.youtube.com/watch?v=8H1TCbW0LJQ) from DevCon V (2 hour video, October 2019)
- Survey of [cross-shard transaction approaches](https://ethresear.ch/t/commit-capabilities-atomic-cross-shard-communication/6509?u=benjaminion) (November 2019)
- [Moving Eth between shards](https://ethresear.ch/t/moving-eth-between-shards-the-problem-statement/6597?u=benjaminion) (December 2019)
- [Statelessness in Eth1.x](https://blog.ethereum.org/2020/01/28/eth1x-files-the-stateless-ethereum-tech-tree/) WHile primarily focused on Eth1, this is an excellent primer on the issues around statelessness in blockchain protocols, which is highly relevant to Eth2 as well (January 2020)
_[Missing: LMD GHOST, stateless clients, RANDAO, swap or not shuffle]_
If you really want to go down the rabbit hole, then the entrance can be found at the [Ethereum Sharding Research Compendium](https://notes.ethereum.org/s/H1PGqDhpm) (April 2019). Explore all that and you will know as much about Ethereum 2.0 as anyone on the planet.
## Research background
- [Casper FFG paper](https://arxiv.org/pdf/1710.09437.pdf) (January 2019)
- The [Casper + GHOST](https://github.com/ethereum/research/blob/master/papers/ffg%2Bghost/paper.pdf) paper, aka GASPER (October 2019)
- [BLS Signature Aggregation](http://crypto.stanford.edu/~dabo/papers/aggreg.pdf) (2003)