benchmarks for VDF

[omershlo]

add benchmarks for different parameters and measure the absolute and relative times of Eval and Verify

If possible, compare it to: https://github.com/harmony-one/vdf https://github.com/poanetwork/vdf

[jon-chuang]

How performant does one expect the library to be compared to, say Sundersoft, which won the Chia networks competition?

[omershlo]

This is a good question!

1. The foundations of this library are built using Pari which is optimised c code for class group operations
2. However, I suspect that our translation from/to Pari to/from our GMP bigint is not so efficient.
3. BigInt operations are suppose to be reasonably efficient.

Overall I would assume the code will be slower than Sundersoft, but :

1. probably within same order of magnitude
2. specifically for VDF, the gap quality between generating and solving will be the similar
3. There is a LOT of room for improvement in this library

[0xmountaintop]

This is a good question!

1. The foundations of this library are built using Pari which is optimised c code for class group operations
2. However, I suspect that our translation from/to Pari to/from our GMP bigint is not so efficient.
3. BigInt operations are suppose to be reasonably efficient.

Overall I would assume the code will be slower than Sundersoft, but :

1. probably within same order of magnitude
2. specifically for VDF, the gap quality between generating and solving will be the similar
3. There is a LOT of room for improvement in this library

poanetwork also has this discussion: https://github.com/poanetwork/vdf/issues/13

MPIR may be a better choice over GMP & Pari