(On a Intel(R) Core(TM) i7-8705G CPU @ 3.10GHz, with 32 GB of RAM)

- before:
```
sign_poseidon           time:   [383.01 ms 384.46 ms 385.98 ms]
verify_poseidon         time:   [250.56 ms 251.46 ms 252.43 ms]
```

- current:
```
sign_poseidon           time:   [973.38 us 973.83 us 974.41 us]
verify_poseidon         time:   [835.34 us 839.94 us 845.29 us]
```

sign_poseidon: `394x` improvement
verify_poseidon: `300x` improvement