PrimeChecker — Bytecode Verification

Proof of source code for PrimeChecker:

• 0x66D796E7AE8608BbA361c97bA7682689cc5Bf320 — deployed Aug 7 2015 (block 48,790)
• 0xDAE5047277a2cc3d0013Fc0cF4A12817b9b85C33 — deployed Aug 7 2015 (block 48,827)

Both contracts share identical bytecode, deployed 9 minutes apart by 0x6b4971... — day 8 after Frontier genesis.

Contract

A trial-division primality checker: call smallestfactor(n) and it returns n if n is prime, or the smallest factor if composite. One of the earliest mathematical utility contracts deployed on Ethereum. The two identical deployments suggest the author was testing.

Compiler

Field	Value
Image	soljson-v0.1.1+commit.6ff4cd6 (JavaScript, via node.js)
Optimization	OFF
Runtime size	154 bytes

Verification

Requires: node.js

./verify.sh

Expected: ✅ EXACT MATCH — PrimeChecker bytecode verified (154 bytes)

The script downloads soljson-v0.1.1+commit.6ff4cd6.js from binaries.soliditylang.org if not already present.

Key Insights

1. Day 8 after Frontier — among the earliest contracts ever deployed on Ethereum mainnet
2. smallestfactor is all-lowercase — unusual function naming for the era; not found in any public 4-byte selector database (0xb19eaf1e)
3. Trial division loop — for (uint i = 2; i * i <= n; i++) — returns i on first factor found, n if prime
4. Two identical deployments — same bytecode at two addresses, 9 minutes apart, from the same deployer; consistent with a developer testing their own contract
5. No storage, no state — purely computational; pure function before pure existed as a keyword

Selectors

• b19eaf1e → smallestfactor(uint256) — not in any public 4-byte selector database

Files

• PrimeChecker.sol — Solidity source
• runtime.hex — Expected runtime bytecode (154 bytes)
• verify.sh — Verification script (requires node.js)