A Fistful of Bitcoins: Characterizing Payments Among Men with No - PowerPoint PPT Presentation

Heuristic 2 To identify change addresses, look for “one-time” output address pk If there is exactly one such address, label it the change address This isn’t conservative enough! • Wait a week before identifying address 15

Heuristic 2 To identify change addresses, look for “one-time” output address pk If there is exactly one such address, label it the change address This isn’t conservative enough! • Wait a week before identifying address • Ignore “self-change” addresses 15

Heuristic 2 To identify change addresses, look for “one-time” output address pk If there is exactly one such address, label it the change address This isn’t conservative enough! • Wait a week before identifying address • Ignore “self-change” addresses • Manually inspect some remaining addresses 15

Data collection 16

Data collection Engaged in transactions with: 16

Data collection Engaged in transactions with: • Exchanges 16

Data collection Engaged in transactions with: • Exchanges • Vendors 16

Data collection Engaged in transactions with: • Exchanges • Vendors • Mining pools 16

Data collection Engaged in transactions with: • Exchanges • Vendors • Mining pools • Gambling sites 16

Data collection Engaged in transactions with: • Exchanges • Vendors • Mining pools • Gambling sites • Wallet services 16

Data collection Engaged in transactions with: • Exchanges • Vendors • Mining pools • Gambling sites • Wallet services • Mix services 16

Data collection Engaged in transactions with: • Exchanges • Vendors • Mining pools • Gambling sites • Wallet services • Mix services Scraped published tags 16

Data collection Engaged in transactions with: • Exchanges • Vendors • Mining pools • Gambling sites • Wallet services • Mix services Scraped published tags Found addresses discussed on forums 16

Exchanges 17

Vendors 18

Published tags 19

Trolling Bitcoin forums 20

Trolling Bitcoin forums 20

Trolling Bitcoin forums 20

Putting it all together 21

Putting it all together Transact us them 21

Putting it all together Transact us them 21

Putting it all together Cluster Transact us them 21

Putting it all together Cluster Transact us them 21

Putting it all together Cluster Bootstrap Transact us them 21

Putting it all together Cluster Bootstrap Transact us them 21

Putting it all together Cluster Bootstrap Transact us them Interacted with 31 MtGox addresses, tagged 518,723! Participated in 344 transactions and tagged 1.3M public keys 21

Outline Cryptographic background How does Bitcoin work? Analysis Results Results Conclusions Overall statistics Tracking cluster activity 22

Clustering using our heuristics 23

Clustering using our heuristics bicycle wheel with gambling at center 23

Clustering using our heuristics strongly connected component with most of our named users bicycle wheel with gambling at center 23

Following bitcoins 24