, 16 tweets, 4 min read Read on Twitter
A first technical impression of Libra, aka "facebook coin", compared against Eth 1 and Eth 2.

#ethereum #libra #eth2
0. data keying:
- 32 byte keys seem to be the future. Not only Ethereum 2 is using them in SSZ, Libra will use them for account keys
- static generalized indices, can't find much for "light" clients, you're either a powerful validator, or a user (to be expected)
1. Hashing/merkleization:
- SHA3-256. Not like eth1 (older SHA3), or ETH2 (SHA2-256, like bitcoin)
- No derived merkle structures ("hash tree root" in Eth 2) just bare binary trees.
- Sparse binary trees, with leafs moved upwards. Efficient, but not static enough (important too)
2. Signatures
No BLS (like Eth 2), nor ECDSA (like Eth 1). EdDSA, edwards 25519 instead. Seems good for small values (roots), but like possibilities with BLS better.
Signing transactions seems to be very similar to Eth 1. More on that ⬇️
3. Transactions
Transactions are pretty much the same as in Eth 1.
- "Sender address, pubkey": tx.from
- "Program": tx .to ++ .data
- "Gas price": tx.gasPrice, just in Libra coins.
- "Max gas": tx.gasLimit
- "seq nr": tx.nonce, incr. account value
4. Contracts/VM
"Modules": Like a smart-contract in Eth 1. Published through tx .data. But stays attached to sender account.
Their "MOVE" VM is interesting, has strong "asset" support. Really just a take on var-ownership/capabilities/mutability. Can be ported to an Eth2 EE.
5. Logs
"Events". Not readable from contracts, cheap, used to read changes live or back in history. Same as Eth 1.
Txs have an "event tree", instead of blocks. More ⬇️
6. Blocks
No blocks, but batches. Everything is sequential, but abstracted away from blocks. No POW anyway. And event roots etc. are with each transaction in "Transaction-Info" instead.
7.1 Serialization
They may have looked at our Simple-Serialize. But older version, without offsets for lookup efficiency (SOS style) or per-list max-sizes for static generalized indices. They do cover sparse lists as a simple TreeMap, encode key, encode value, repeat.
more ⬇️
See github.com/libra/libra/bl…
"SimpleSerializer" vs. old SSZ: github.com/ethereum/eth2.… More ⬇️
7.2 Sparse serialization
In Eth 2 we have offsets, so you don't have to deserialize a full MB (or more!) when only reading a small value/part.
In addition, Eth 2 is looking to do "sparse lists"; tree-maps by fixed-length index, with index lookup in header, similar to offsets.
8.1 Leader election.
In Eth1 we have miners doing POW
In Eth2 we have randao temporarily, and are going for VDF based shuffled committees, doing POS.
In Libra..., we elect leaders, and "validators" send blocks to the leader. More ⬇️
8.2 "the leader of a round is determined by the proposer of the latest committed block using a verifiable random function". Not a VDF, or randao, just a func with the previous block as input. I hope it's not just a hash. Imagine paying 10M for a spot and others manipulate that...
9. All in all... ok ish, and I can see Move growing, getting dev tooling / support. But if so, we'll just port it over to an Eth 2 execution environment, and let the market play with it.
10. Some links:
technical stuff: libra.org/en-US/open-sou…
GitHub: github.com/libra/libra
whitepaper: libra.org/en-US/white-pa…
* _No_ static generalized indices
Missing some Tweet in this thread?
You can try to force a refresh.

Like this thread? Get email updates or save it to PDF!

Subscribe to protolambda
Profile picture

Get real-time email alerts when new unrolls are available from this author!

This content may be removed anytime!

Twitter may remove this content at anytime, convert it as a PDF, save and print for later use!

Try unrolling a thread yourself!

how to unroll video

1) Follow Thread Reader App on Twitter so you can easily mention us!

2) Go to a Twitter thread (series of Tweets by the same owner) and mention us with a keyword "unroll" @threadreaderapp unroll

You can practice here first or read more on our help page!

Follow Us on Twitter!

Did Thread Reader help you today?

Support us! We are indie developers!

This site is made by just three indie developers on a laptop doing marketing, support and development! Read more about the story.

Become a Premium Member ($3.00/month or $30.00/year) and get exclusive features!

Become Premium

Too expensive? Make a small donation by buying us coffee ($5) or help with server cost ($10)

Donate via Paypal Become our Patreon

Thank you for your support!