A provably-fair commit-reveal gambling contract from the Ethereum dapp-bin, deployed 47 days after Frontier genesis.
Historical Significance
One of the earliest on-chain gambling contracts on Ethereum, written in Serpent by the Ethereum core team and included in the official dapp-bin repository. Deployed just 47 days after Frontier genesis, it demonstrates cryptographic commit-reveal randomness at a time when the concept was being actively developed for blockchain use. A direct predecessor to the commit-reveal patterns used by later provably-fair gaming protocols.
Context
Ethereum's Frontier mainnet launched July 30, 2015. The first weeks and months saw core developers actively building and deploying example contracts to demonstrate capabilities. The dapp-bin repository was the official showcase for Serpent-based dapps. This gamble contract was deployed by address 0x5ed8cee6b63b1c6afce3ad7c92f4fd7e1b8fad9f at block 235,543 on September 15, 2015.
Key Facts
Description
A provably-fair on-chain gambling contract from the dapp-bin example repository. Players place bets by submitting a key and probability. The house pre-commits to a seed hash, then reveals the seed to determine outcomes via sha3(seed || player_key) divided by a normalization constant. Winners receive payouts automatically during the reveal phase. Written in Serpent, the smart contract language developed alongside Ethereum before Solidity matured.
Source Verified
Full 1136-byte creation transaction input matches compiled output byte-for-byte. Source: dapp-bin/gamble.se commit d94b22e. Compiler: Serpent fd9b0b6 (2015-09-06). Key findings: send() uses 5000 gas stipend (pre-EIP-150), event Bet() requires typed ABI params (bettor:address, value:uint256, prob_milli:uint256) for correct keccak topic hash, bytes32 function arguments supported. The init code deploys 1114 of 1118 compiled runtime bytes, skipping a 4-byte unreachable dead-code epilogue.
Historian Categories
Heuristic Analysis
The following characteristics were detected through bytecode analysis and may not be accurate.
Frontier Era
The initial release of Ethereum. A bare-bones implementation for technical users.
Bytecode Overview
Verified Source Available
Source verified through compiler archaeology and exact bytecode matching.
View Verification ProofShow source code (Serpent)
data owner
data curseed
data curseedExpiry
data bets[2**100](bettor, bettor_key, potential_winnings, prob_milli)
data numBets
data depositLocked
event Bet(bettor:address, value:uint256, prob_milli:uint256)
event NewSeed()
def init():
self.owner = msg.sender
def get_curseed():
return(self.curseed)
def set_curseed(old_value:bytes32, new_seed:bytes32):
if msg.sender != self.owner:
return(0)
if old_value != sha3(self.curseed) and self.curseed != 0:
return(0)
i = 0
numBets = self.numBets
DIVCONST = 115792089237316195423570985008687907853269984665640564039457584007913129639
while i < numBets:
rnd = ~div(sha3([old_value, self.bets[i].bettor_key]:arr), DIVCONST)
if rnd < self.bets[i].prob_milli:
send(self.bets[i].bettor, self.bets[i].potential_winnings)
self.bets[i].bettor = 0
i += 1
self.numBets = 0
self.curseed = new_seed
self.curseedExpiry = block.timestamp + 86400 * 2
log(type=NewSeed)
return(1)
def emergency_withdraw():
if block.timestamp <= self.curseedExpiry:
return(0)
i = 0
numBets = self.numBets
while i < numBets:
send(self.bets[i].bettor, self.bets[i].potential_winnings * self.bets[i].prob_milli / 1000)
self.bets[i].bettor = 0
i += 1
suicide(0xde0b295669a9fd93d5f28d9ec85e40f4cb697bae)
def bet(bettor_key:bytes32, prob_milli):
if self.numBets >= 100:
send(msg.sender, msg.value)
return(-1)
potential_winnings = msg.value * 1000 / prob_milli
if self.balance - self.depositLocked < potential_winnings:
send(msg.sender, msg.value)
return(-2)
self.depositLocked += potential_winnings
betIndex = self.numBets
self.bets[betIndex].bettor = msg.sender
self.bets[betIndex].bettor_key = bettor_key
self.bets[betIndex].potential_winnings = potential_winnings
self.bets[betIndex].prob_milli = prob_milli
self.numBets = betIndex + 1
log(type=Bet, msg.sender, msg.value, prob_milli)
return(betIndex)
def withdraw():
send(self.owner, self.balance - self.depositLocked)