zksbt : design V2

zksbt V1 问题

zksbt V1集成(POMP)下来发现新的需求

同一个category/attribute的pomp要能够mint多次，通过verify time来区分.
pomp幅度(range)较多.
npo/pomp 上新较多，减少合约上新流程. (第一个mint时创建group)

semaphore 现有的merkle tree membership prove不太适用 :

NPO/POMP上新类别多，特别是POMP，多条链，各种资产，各种不同的Range，每个组合都是一个semaphore group，每次上新，需要发送大量交易
depth 32 group中add member需要>1M的gas cost(ETH 2000U, gas price 0.1G, 约为0.2U)

V2

merkle tree group保留on-chain privacy verify的可能性
- depth 16, 降低mint gas
- leave存储 hash(identity, sbt_id, verify_time)
sbt id 唯一
hash(attribute), 作为public input.
- 上新只需要上category, 而range作为sbt的metadata信息. privacy verify时使用.
circuit 中验证timestamp
- privat verify_time >= given public begin_verify_time
- privat verify_time <= given public end_verify_time,

flowchart LR
    %%style at fill:#EE784E,stroke:#EE784E,stroke-width:1px
    %%style ar fill:#EE784E,stroke:#EE784E,stroke-width:1px
    %%style vt fill:#EE784E,stroke:#EE784E,stroke-width:1px
    style sbt fill:#EE784E,stroke:#EE784E,stroke-width:1px

    style vt fill:#EE784E,stroke:#EE784E,stroke-width:1px

    style H6 fill:#85E8C2,stroke:#85E8C2,stroke-width:1px

    style GT1 fill:#85E8C2,stroke:#85E8C2,stroke-width:1px

    style GT2 fill:#85E8C2,stroke:#85E8C2,stroke-width:1px

    style beginv fill:#15E8C2,stroke:#15E8C2,stroke-width:1px

    style endv fill:#15E8C2,stroke:#15E8C2,stroke-width:1px

    style attribute fill:#15E8C2,stroke:#15E8C2,stroke-width:1px

s(PRIV - Siblings) & pi(PRIV - Path Indices) --> M1((MT Verifier)) --> mr(PUB - MT Root of asset/range)
  it(PRIV - Identity Trapdoor) & in(PRIV - Identity Nullifier) --> H2((Poseidon Hash)) --> |Secret| H3((Poseidon Hash)) --> |Identity Commitment| H6((Poseidon Hash)) --> |Per SBT Identity| mr
 
 %%at(PUB asset_type) & ar(PUB - asset_range) &
 %%vt(PUB - verify_time) &
sbt(PRIV - zkSBT_id) --> H6
vt(PRIV - verify_timestamp) --> H6
attribute(PUB - attribute) --> H6



in(PRIV - Identity Nullifier) & en(PUB - External Nullifier) --> H4((Poseidon Hash)) --> n(PUB - Nullifier)


vt --> GT1
beginv(PUB - beginVerifyTimestamp) --> GT1

endv(PUB - endVerifyTimestamp) --> GT2
vt --> GT2

%%sig(PUB - Signal Hash) --> S1((Square))

zksbt : design V2

zksbt V1 问题​

V2​

zksbt V1 问题

V2