2019-05-17, 13:30–16:30, Workshop 4 (Salon du president)
Hands-on workshop to understand bitcoin fundamentals, learn clustering techniques, trace transactions in the blockchain and extract bulk transactions via the GraphSense open-source platform.
For this workshop, participants do not need to have prior knowledge about bitcoin. The workshop is divided in three strategic sections.
Section 1–Bitcoin fundamentals – 45 minutes
- Private/public keys and bitcoin addresses
- Mining bitcoins, maintaining the blockchain and transaction fees
- How to buy bitcoins and types of wallets that exists
- Platforms that exist to follow bitcoin transactions (blockchain.info, walletexplorer, bitcluster and GraphSense).
Participants will download the Electrum software wallet and I will transfer bitcoin to each of their generated addresses (small amounts, obviously). They will be able to track the transaction in the blockchain using blockchain.info.
Section 2 – Clustering, tagging and basic techniques to trace transactions – 1 hour
- Presentation of clustering heuristics (how to group addresses together)
- Tagging clusters leading to deanonymization
- Presentation of the GraphSense open-source platform
- Presentation of the kinds of clusters that exist
Using a dozen of bitcoin addresses, participants will be tasked to trace transactions and conclude whether it is possible to know where the money was cashed out and what can be inferred from the money flow.
Section 3 – Advanced techniques behind tracing transactions using GraphSense API and Python open-source libraries – 1 hour
- Presentation of a technique to trace transactions based on outgoing/incoming relationships
- Presentation of the GraphSense open-source API
- Presentations of the scripts used to extract information and the open-source tools used to graph large amounts of money flows
For this exercise, an environment will be provided to participants with the tools and the data installed. If needed, they can easily replicate the environment at home.
Participants will be tasked to extract information from a list of addresses using the GraphSense open source API. Then, they will graph the data based on the techniques presented above.