Co to jest FHE?

contract Vault {
  // stan zaszyfrowany — tylko właściciel odczyta
  state {
    balance: ct_int,
    owner:   address,
    locked:  int      // bool jako 0/1
  }

  fn deposit() {
    require(caller == owner)
    self.balance = ct_add(
      self.balance,
      encrypt(value)   // value = OCT w tx
    )
  }

  fn withdraw(amount: ct_int) {
    require(caller == owner)
    require(ct_gte(self.balance, amount))
    self.balance = ct_sub(self.balance, amount)
    send(caller, decrypt(amount))
  }
}

contract SealedVote {
  state {
    votes_yes: ct_int,
    votes_no:  ct_int,
    ended:     int
  }

  fn cast(encrypted_vote: ct_bool) {
    require(self.ended == 0)
    // ct_bool: 1=tak, 0=nie
    self.votes_yes = ct_add(
      self.votes_yes,
      ct_and(encrypted_vote, encrypt(1))
    )
  }

  fn finalize() {
    require(caller == admin)
    self.ended = 1
    // wynik: decrypt(votes_yes) > N/2
  }

  fn result() -> ct_bool {
    require(self.ended == 1)
    return ct_gte(votes_yes, votes_no)
  }
}