0xabf6...c184

Utility

0xabf65a51c7ad...4be38072c184

DAO ForkExact Bytecode MatchEdit this contract

Deployed September 19, 2016 (9 years ago)Block 2,286,851

The transfer and allowance logic of the Devcon 2 attendee token, kept in a library

DAO Fork EraVerified Source

Historical Significance

Non fungible token transfer rules written more than a year before ERC-721, and put in a library so the token contract could stay a thin shell over them.

Context

Deployed in the Homestead era, in the weeks around Devcon 2 in Shanghai.

Key Facts

Deployer

Piper Merriam(0xd3cda9...293601)

Deployment Block

2,286,851

Deployment Date

Sep 19, 2016, 08:48 AM

Code Size

541.0 B

Deployment Transaction: 0x372d05ee12ee280e...3d616bc2421bc46a

Description

TokenLib holds the state and the rules for the Devcon 2 attendee token: who owns which token, who is approved to move it, and the transfer, transferFrom and approve paths that check those two things. The token contract keeps no logic of its own and calls into this library, which is why the library is a separate deployment. Each token is identified by a bytes32 rather than an amount, because every attendee got a distinct one. Deployed on 19 September 2016 by 0xd3cda913deb6f67967b99d67acdfa1712c293601, the account of Piper Merriam, and recovered from pipermerriam/devcon2-token.

Source Verified

Exact bytecode match(541 bytes)

Compiler: v0.3.6-

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Heuristic Analysis

The following characteristics were detected through bytecode analysis and may not be accurate.

Detected Type: Utility

DAO Fork Era

The controversial fork to recover funds from The DAO hack.

Block span: 1,920,000 — 2,462,999

July 20, 2016 — October 18, 2016

Bytecode Overview

Opcodes541

Unique Opcodes119

Jump Instructions28

Storage Operations7

Verified Source Available

Source verified through compiler archaeology and exact bytecode matching.

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Show source code (Solidity)

// Submitted by EthereumHistory (ethereumhistory.com)
library TokenLib {
    struct Token {
        string identity;
        address owner;
    }

    function id(Token storage self) returns (bytes32) {
        return sha3(self.identity);
    }

    function generateId(string identity) returns (bytes32) {
        return sha3(identity);
    }

    event Transfer(address indexed _from, address indexed _to, bytes32 _value);
    event Approval(address indexed _owner, address indexed _spender, bytes32 _value);

    function logApproval(address _owner, address _spender, bytes32 _value) {
        Approval(_owner, _spender, _value);
    }

    function logTransfer(address _from, address _to, bytes32 _value) {
        Transfer(_from, _to, _value);
    }
}