BCHNBTC
BCHN / Bitcoin
crypto

Copying here:
---
For ZKP-interested devs: BCH is uniquely well suited to trustless on-chain verification of STARKs vs. pairing-based proofs. It may be wise to leapfrog EC pairing and start with STARKs.
Also beware of the "L1 can't scale" zeitgeist: BCH hasn't made ETH's scaling mistakes, and ZKPs aren't a prerequisite for BCH's global-reserve-currency scale.
Various intro material for BCH devs:
- https://starkware.co/integrity-matters-blog/why-im-excited-by-circle-stark-and-stwo/
- https://l2ivresearch.substack.com/p/recursive-proofs-in-stwo-part-i
- https://l2ivresearch.substack.com/p/recursive-proofs-in-stwo-part-ii
---
Also, PSA, you can "SIMD within a register" using BCH's very long VM numbers. Maybe useful for reducing opCost (and resulting TX sizes) by replacing naive MUL/DIV/MOD with cheap arithmetic/shifts in FRI and other algorithms: https://aszepieniec.github.io/stark-anatomy/fri
---
Also, use OP_IFDUP to save a byte here and there! E.g. a loop counting down:
```CashAssembly
// Add many items to the stack
<5> OP_BEGIN
OP_1SUB
OP_TOALTSTACK
// -- anything on main stack
<1>
// -- end
OP_FROMALTSTACK
OP_IFDUP OP_NOT
OP_UNTIL
```
More: https://github.com/bitjson/bch-loops
---
That SIMD/SWAR trick seems most likely to be useful for 128+ "lane" FRI folds, but might also be useful for slightly more opCost-efficient Poseidon2 rounds (if using Poseidon2 reduces overall byte length vs. SHA-256). I don't think it offers savings for NTTs without refining MUL's cost (and commensurately stricter VM performance requirements), but please prove me wrong and/or CHIP it. 🚀
Of course, if you're at this level of optimization, consider CHIPing a reduction in Base Instruction Cost, too. The 2025 upgrade's 100 is "crawl before walking", and IIRC BCHN can already 10x it (i.e. base cost of 10).

Copying here:
---
For ZKP-interested devs: BCH is uniquely well suited to trustless on-chain verification of STARKs vs. pairing-based proofs. It may be wise to leapfrog EC pairing and start with STARKs.
Also beware of the "L1 can't scale" zeitgeist: BCH hasn't made ETH's scaling mistakes, and ZKPs aren't a prerequisite for BCH's global-reserve-currency scale.
Various intro material for BCH devs:
- https://starkware.co/integrity-matters-blog/why-im-excited-by-circle-stark-and-stwo/
- https://l2ivresearch.substack.com/p/recursive-proofs-in-stwo-part-i
- https://l2ivresearch.substack.com/p/recursive-proofs-in-stwo-part-ii
---
Also, PSA, you can "SIMD within a register" using BCH's very long VM numbers. Maybe useful for reducing opCost (and resulting TX sizes) by replacing naive MUL/DIV/MOD with cheap arithmetic/shifts in FRI and other algorithms: https://aszepieniec.github.io/stark-anatomy/fri
---
Also, use OP_IFDUP to save a byte here and there! E.g. a loop counting down:
```CashAssembly
// Add many items to the stack
<5> OP_BEGIN
OP_1SUB
OP_TOALTSTACK
// -- anything on main stack
<1>
// -- end
OP_FROMALTSTACK
OP_IFDUP OP_NOT
OP_UNTIL
```
More: https://github.com/bitjson/bch-loops
---
That SIMD/SWAR trick seems most likely to be useful for 128+ "lane" FRI folds, but might also be useful for slightly more opCost-efficient Poseidon2 rounds (if using Poseidon2 reduces overall byte length vs. SHA-256). I don't think it offers savings for NTTs without refining MUL's cost (and commensurately stricter VM performance requirements), but please prove me wrong and/or CHIP it. 🚀
Of course, if you're at this level of optimization, consider CHIPing a reduction in Base Instruction Cost, too. The 2025 upgrade's 100 is "crawl before walking", and IIRC BCHN can already 10x it (i.e. base cost of 10).