Chiavdf

Changed

- Removed inefficient ConvertIntegerToBytes() and ConvertBytesToInt() functions, use GMP library's mpz_export/mpz_import for big integers and simple helper functions for built-in integer types. The latter are taken from chiavdf.
- Require compressed forms to be encoded canonically when deserializing. This should prevent potential grinding attacks where some non-canonical encodings of a compressed form could be used to change its hash and thus the next challenges derived from it. Canonically encoded compressed forms must be reduced and must produce the same string when deserialized and serialized again.

0.15.1bluebox

Added

- Add form compression, use it in Python bindings and VDF client. Using compressed representation of quadratic forms reduces their serialized size from 130 to 100 bytes (for forms with 1024-bit discriminant). This shrinks the size of VDF outputs and VDF proofs. The form compression algorithm is based on ["Trustless Groups of Unknown Order with Hyperelliptic Curves"](https://eprint.iacr.org/2020/196) by Samuel Dobson, Steven D. Galbraith and Benjamin Smith.
- We now verify form size when deserializing.
- MacOS universal wheels to support MacOS ARM64 are built for Python 3.9.

Changed

- This is a breaking change from the 0.13.x series.

Added

- We now build both MacOS x86_64 and MacOS universal wheels.