Network Privacy in Blockchains

2018.06.27 13:00-14:00 - Isis Agora Lovecruft - Part 1

This workshop about the privacy in propagation protocol within blockchain networks and de-anonymization of transactions.

(Go up the path in the repo for more exciting papers)

Separate groups discussion on the network anonymization protocols (Some are fictional at this point):

Dandelion
- MimbleWimble / Grin
Whisper Protocol (Ethereum)
Tumblers
Noise networks
Use Tor / Use Signal
Use Wireguard
Broadcasted Encryption
Randomized Transaction Handling
Kovri - used in Monero. Onion routing style like tor but different approach (DHT Node discovery, Uni-directional routing (closer to free route mixnets), designed for low latency networks, probably works well for P2P but may not work well for client-server architecture).
Mixnets

Each group posted their proposals on the window and the rest put star stickers on their preferred proposals:

Top Rated:

Research Ideas:

2018.06.27 14:10-15:10 - Isis Agora Lovecruft - Part 2

... [missed the beginning of the discussion]

Discussion:

Discussion regarding how Dandelion Protocol works, One example: Grin Spec
Timing attacks by an entity that runs multiple (many) nodes in the network
Issue with being always online on the protocols like Signal
Mix networks High latency privacy network, pool up transactions to achieve anonymity
- Chose a route in advance by the client
- None of the nodes have access to where the transaction comes from and leaves to
- Not good when nodes are not consistently online, need more stable networks
- Cascade mixing
  - At least requires one honest node on a path for everyone to use this one path
- Traffic Analysis Resistant Messaging: katzenpost
- Originally designed for e-voting and e-mail
- If used in Blockchain networks, it can't be used for miner nodes, as the high latency might lead to network forks and higher rate for orphaned blocks.
Some discussion on possible attacks such as eclipse attack, sybil attack, 51% attack.