vrf
https://zhuanlan.zhihu.com/p/142624711
https://datatracker.ietf.org/doc/html/draft-irtf-cfrg-vrf-04
https://dash.harvard.edu/bitstream/handle/1/5028196/vadhan_verifrandomfunction.pdf?sequence=2
https://zhuanlan.zhihu.com/p/142624711
https://datatracker.ietf.org/doc/html/draft-irtf-cfrg-vrf-04
https://dash.harvard.edu/bitstream/handle/1/5028196/vadhan_verifrandomfunction.pdf?sequence=2