Add changelog

CHANGELOG.md

@@ -0,0 +1,58 @@
+# Changelog
+
+## Pending
+
+## v0.2.0
+
+This update implements Poseidon, and adds significantly algebraic hash infrastructure.
+The BCS transformation now has an option for proofs of work for shrinking proof size.
+The Fractal RS-IOP has been updated, and is now significantly faster than before.
+
+Many other changes throughout the library.
+
+## v0.1.0
+
+This update implements Fractal, a transparent preprocessing SNARK with a polylog verifier.
+It also includes significant performance and memory improvements.
+
+Aurora has gotten significantly faster. The prover is 2.2 times faster, and the verifier is 2.4 times faster.
+Ligero has gotten 25% faster in both the prover and verifier times.
+The Fractal prover has gotten 20% faster than the stated numbers in the paper.
+
+Some highlights of the optimizations from the update:
+
+Algebra Speedups:
+* FFTs are now Nlog(d) instead of NlogN
+* FFTs now utilize a cache, which halves the number of multiplications
+
+IOP:
+* Switch all codewords to being passed around as shared pointers,
+  which significantly reduces memory consumption
+
+Merkle Tree:
+* It now handles serializing by coset, reducing time to copy memory
+
+LDT Reducer:
+* Improve efficiency of shifting sub-maximal degree oracles
+
+FRI:
+* The prover does a single batch inversion per round,
+  instead of one batch inversion per coset of size 2^{localization param}
+* Optimized the FRI lagrange interpolation equations to further reduce the linear factor
+* The FRI argument size optimizer now accounts for MT pruning, and tends to yield 3% better argument sizes
+
+Rowcheck:
+* Take advantage of Z_H | L being an |H| to 1 map, to speedup computing (1 / Z_H) over L.
+
+Aurora Lincheck:
+* Switched the verifier lagrange interpolation to IFFTs.
+  Despite the worse asymptotics, this concretely performs much better.
+
+Sumcheck:
+* Make the IFFT over a domain of minimal size, instead of the entire codeword
+* Improve efficiency of sumcheck virtual oracles,
+  by checking an equi-satisfiable rational function that is easier to compute
+
+## v0.0.0
+
+Initial release