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Please consider this a security review by a tenured P2P professor: The whitepaper describes a simple and focused system relying on partitioning in an attempt t
by synctext 13y ago
Please consider this a security review by a tenured P2P professor:
The whitepaper describes a simple and focused system relying on partitioning in an attempt to preserve scalability.
Bitmessage has many architectural similarities to Usenet and also offers no valid response to spam. Using a proof-of-work system to combat spam is proposed, but to-date science has not yet seen a working approach anywhere. Details are missing on this vital element plus defenses against the Sybil attack are missing from this design.
Mechanisms such as the "averageProofOfWorkNonceTrialsPerByte" in this system only slow down attacks and do not stop them. Check the impossibility proof by Harvard to see that systems like Bitmessage which react to any message cannot build an effective Sybil defense: http://dash.harvard.edu/handle/1/4907301 http://dash.harvard.edu/handle/1/4907301
So this is known as a hard unsolved problem.
Further diving into the scalability issue is this project thread on their forum:
https://bitmessage.org/forum/index.php?PHPSESSID=8cl6qeafitkac363ufcqma3tp5&topic=3391.0 https://bitmessage.org/forum/index.php?PHPSESSID=8cl6qeafitk...
It would be great if the partitioning concept and algorithms could be explained in detail. It's again a hard problem, even group size estimation in a hostile environment is already non-trivial. So how group consensus is formed to do a break-up is difficult and prone to attacks.
This design is not incentive compatible. TOR has over 50% Bittorrent traffic, it's difficult to stop users from using(abusing?) TOR like that. Systems like Bittorrent and Bitcoin have some incentives, but Bitmessage with broadcasts and proof-of-work might even have a negative incentive for participation. I have seen no mechanism to prevent it's users broadcasting Blueray rips. This would bring down the system, one cluster at a time. Please check this work, it shows how to bring this type of P2P networks down: www.christian-rossow.de/publications/p2pwned-ieee2013.pdf
Publicity like "Bitmessage Sends Secure, Encrypted, P2P Instant Messages" might be nice. It creates a false sense of safety. If you want to protect against NSA snooping, you're up against a real army of crypto experts with decades of experience each.
Nice to see that this project has such an active Github community, 480 closed issues and 1159 commits. But, in my opinion it's back to the drawing boards... Sorry.
Disclaimer: working for 8 years on Tribler, a streaming Bittorrent client.
- awt 13y agoBitmessage's POW concept is not only proposed but implemented and being used in practice.
- berdario 13y agomy2c: The common meme in the bitmessage community is that the POW helps mitigate flooding, but it's not quite there for spam prevention
- richardlblair 13y agoI appreciate the write up, it's why I popped into the thread. That said, at least these folks are trying to protect against the NSA. What do you purpose we all do? Lay down and accept that they watch everything we do? Fuck that. Let's continue to build tools as a community. They may have a lot of people, but our community is bigger. So, fuck them. People should continue to experiment, and try new things until we come up with various way to protect against the god damn NSA.
- synctext 13y agoIndeed, we should not roll over and declare privacy an illusion. A lot of people are experimenting with designs that will never work. It's just wasting programming resources, while projects like Tor starve for volunteers. My research team is currently merging Tor and Bittorrent (http://forum.tribler.org/viewtopic.php?f=2&t=5128&p=8585#p8585 http://forum.tribler.org/viewtopic.php?f=2&t=5128&p=8585#p85...). Clear designs (and lots of them) are more important then experimental code I believe.
- Natanael 13y agoDoesn't I2P fit better, considering the design requirements? Tor would require very significant changes to scale better for high volume traffic, but I2P already handles it reasonably well.
- slashdotaccount 13y agoI wonder why I2P is getting so small amount of love. I've read somewhere that for some reason it's popular only in Russia. It has two working email systems, working Bittorrent and much more. Maybe it lacks a native (C or C++) implementation?
- synctext 13y agoI2P is slow, it has no incentive system like T4T. Try installing it, search for files and watch download speeds. Onion routing and tunnels cost bandwidth. The crowd that is used to Bittorrent speeds (in combo with VPN safety) is not interested in 2 Kbit/sec speeds. Plus the user interface is hard to understand without having attended crypto courses.
- Natanael 13y agoWhat do you think of Bote mail in I2P, which uses DHT for relaying mail? It is set to hold mail in the DHT for 100 days or until fetched by the recipient. It also uses public keys as addresses (ECDSA and NTRU are the options), and all mail is encrypted. I2P provides traffic anonymization, and Bote mail supports letting mails be relayed with random delays to further anonymize the sender by removing time correlation. https://www.i2p2.de https://www.i2p2.de and http://i2pbote.i2p.us http://i2pbote.i2p.us (remove .us if you have I2P installed).
- sadclown 13y agoI would love to see someone give i2p-bote a good analysis. I tried using it a couple of times but wasn't able to ever receive messages successfully. They are advertixing some pretty awesome features though; no content or metadata leakage; it is secure against a global passive adeversary if you use delays between relay hops; parties don't have to be online at the same time to communicate.
- Natanael 13y agoI've never had problems with receiving messages with it. Had I2P been running for at least 20 minutes or so to be able to establish enough connections? Bote can tell you how many Bote nodes it is connected to.
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