A Tale about Bitcoin Anonymity

ZeronightsDefcon Russia

PrivacyForensics

E-commerceAnti-fraud systems

History1982 David Chaum (1990 released DigiCash)

1998 Wei Dai (B-Money)

1998 Nick Szabo BitGold

2008 Satochi Nakamoto (2009 released Bitcoin)

Basics• Bitcoind

• Public and private keys

• Address

• Wallet

• Coin

• Transaction

• Block

Concerns• Privacy – nobody knows what you are doing

• Anonymity – nobody know who are you

• Stealing of bitcoins

• Unfair mining

• Malware

• Fraud

Block Chain

Block Chain

Client• IP broadcasting with transaction

• Web services track users

• Government unlimited power

Balance• Virtual currency becomes offline money

• Initial deposit have to be anonymous

• Unlimited amount of addresses

• Change

Laundry• Give one money, get another money

• Works with many transactions flow only

• Effective with small transactions

• Problem of trust

Alternatives• Dark Wallet

• Zerocoin

• Forks

Thanks!