2024.6.24 - 2024.6.30

2024.6.30

Robin discovered an interesting project on Delving Bitcoin:https://github.com/dgpv/bsst(Python language).

• The project is positioned as: B'SST: Bitcoin-like Script Symbolic Tracer

• It can symbolically execute opcodes, track the constraints imposed on values operated by opcodes, and show

• conditions of script execution, possible failures, and potential data values, etc.

• Supports Bitcoin script and Elements script.

• Helps in analyzing and revealing potential issues in scripts.

2024.6.28

The official BitVM team has recently significantly optimized the compilation speed of therust-bitcoin-script library(better_scripts branch) and the Script size of the Fflonk Verifier and Groth16 Verifier.

• Currently, the Script size of the Groth16 Verifier has been reduced from approximately 7GB to about 4GB; the script compilation speed has been reduced from over an hour to about 70 seconds.

• Currently, the Script size of the Fflonk Verifier has been reduced from approximately 5.6GB to about 3.2GB; the script compilation and execution speed has been reduced from over half an hour to about 150 seconds.

2024.6.27

The BitVMX team released a blog sharing their thoughts on optimizing BitVM SHA256 script size:https://bitvmx.org/knowledge/optimizing-algorithms-for-bitcoin-script

• For various existing algorithm implementations, simply translating normal implementations is not feasible, as the cost structure of Bitcoin scripts is completely different.

• Clever application of lookup tables, with dynamic loading and unloading, to optimize.

• The 1000 limit of the stack is one of the biggest challenges.

• Logical operations are commutative (x & y == y & x), which can save almost half of the logical table. Implemented OP_MAX with 5 opcodes.

• Currently, BitVMX can reduce SHA256 from 516K to 344K to 296K; Blake3 from 103K to 45K.

• They have open-sourced the stack debugging tool:https://github.com/FairgateLabs/rust-bitcoin-script-stack(Rust) library.