TLOSHiddenThreshold.sol - Hidden voting threshold example

[igor53627]

Parent Issue

Closes part of #47

Description

Build a hidden threshold voting contract where the exact threshold/quorum for a decision is obfuscated, but votes themselves are public.

Use Case (from iO "Voting & Private State")

Traditional voting exposes thresholds, enabling strategic voting. TLOS enables:

• Hidden decision threshold inside obfuscated circuit
• Votes are public (on-chain)
• Outcome only revealed when threshold is crossed
• Voters don't know exactly how many more votes are needed

Example Flow

Voters                           Contract                          Observer
   |                                |                                  |
   | vote(yes/no)                   |                                  |
   |------------------------------->| tallies are public               |
   |                                |                                  |
   | vote(yes/no)                   |                                  |
   |------------------------------->|                                  |
   |                                |                                  |
   | checkOutcome(puzzle)           |                                  |
   |------------------------------->|                                  |
   |                                | evaluates hidden threshold       |
   |                                | if crossed: emit Decided(result) |
   |                                |------ Decided(PASSED) ---------->|

Key Features

• Public vote tallies (yes/no counts)
• Hidden threshold logic in TLOS circuit
• Multiple threshold types:
  • Simple majority with hidden quorum
  • Supermajority with hidden percentage
  • Complex multi-condition logic
• Puzzle required to check outcome (prevents spamming checks)

Security Model

• What's hidden: Exact threshold/quorum/conditions
• What's public: Individual votes, current tallies
• Guarantee: 2^76 minimum to brute-force threshold before voting ends
• Note: NOT private voting - votes are visible, only threshold is hidden

Why Hide Thresholds?

• Prevents strategic voting ("we only need 2 more votes")
• Prevents last-minute coordination attacks
• Adds uncertainty to governance manipulation
• Useful for games, auctions, competitive scenarios

Implementation Notes

• Threshold encoded in puzzle derivation or circuit output
• Consider: reveal threshold after decision (post-hoc transparency)
• Voting deadline to bound the hiding period

Acceptance Criteria

• Contract compiles and passes tests
• Multiple threshold types demonstrated
• Clear distinction: votes public, threshold hidden
• Gas benchmark documented