#122: VM Limits feat. Jason Dreyzehner

The Bitcoin Cash Podcast

Discussion of proposed BCH '25 "Targeted VM Limits" upgrade, with prominent BCH developer & CHIP author Jason Dreyzehner. We get into the historical context, rationale, and details of VM Limits. We also discuss BigInts, CashTokens retrospect, LibAuth, ZCEs, Looping and more. Enjoy, and please share your thoughts in the comments.

Links:

Jason Dreyzehner on Twitter: https://x.com/bitjson

bitjson's blog: https://bitjson.com/

CHIP 2021-05 Targeted Virtual Machine Limits: https://bitcoincashresearch.org/t/chip-2021-05-targeted-virtual-machine-limits/437

CHIP 2024-07 BigInt: High-Precision Arithmetic for Bitcoin Cash: https://bitcoincashresearch.org/t/chip-2024-07-bigint-high-precision-arithmetic-for-bitcoin-cash/1356

Episode slides: https://docs.google.com/presentation/d/1wLaTFfq4PQ1dfTs2EMsNxGMQOZKZMIpW/edit?usp=sharing&ouid=100290143879929950045&rtpof=true&sd=true

Donations:

bitcoincash:qzm59xkz4pkqgpakkpvjcrsffu4gtjxdju7hq6q30h

Sponsors:

Thank you very much to our flipstarter contributors: https://bchpodcastflipstarter.cash/en

General Protocols: https://generalprotocols.com and https://bchbull.com

Socials:

Website: https://www.bitcoincashpodcast.com

Timestamps:

00:00 Podcast starts

00:38 Intro

01:50 Jason’s intro

06:34 Thoughts on ABLA upgrade

10:20 VM Limits: overview

13:40 VM Limits: rationale

17:31 VM Limits: Satoshi’s work

32:15 Differences among implementations

39:26 BTC overflow bug

45:00 CHIP: Targeted VM Limits

49:35 VM Limits + Big Integers

52:28 Big Ints CHIP relation to VM Limits CHIP

1:00:18 Benchmarking worst case contracts with LibAuth

1:02:24 Timing: 2025 vs 2026

1:10:35 Testing process

1:16:55 Zero-Confirmation Escrows (ZCE) and Looping

1:20:35 0-confirmations, miner incentives, and finality

1:25:10 Loops and UTXO commitments

1:34:32 CashTokens

1:39:17 Mathieu’s Q: Zero knowledge proof verifier?

1:42:33 Sidechain necessary for prediction market apps?

1:49:29 Jason’s message to the community

1:51:00 Podcast supporter appreciation

1:52:03 Shoutouts and outro

#bitcoin #bitcoincash #bch #btc #crypto #cryptocurrency #cbdc ▪️