Bad Guys == Anyone blocking or monitoring a persons access to knowledge Q: What is to stop operatives working for the bad guys from running tor proxies from 3rd party locations? Granted, they would only be able to sample a portion of the traffic, but traffic that they did sample could lead to identification of users. It doesn't seem like it would be that hard to match up the encrypted client side requests with the un-encrypted outgoing requests.
PA: The only solution I can think of here is centralized control of the proxy network provided by a press/media sponsorship model as opposed to the bandwidth volunteer model. It's to easy for bad guys to infiltrate the volunteer network. It would also be easier to swap in and out new proxies as they are blocked. runtime selection of alternative proxy networks would be a nice feature. Q: I have noticed lists like: http://proxy.org/tor.shtml that appears to be a list of tor proxies. What's to stop the bad guys from blocking the entire proxy database? My understanding is that countries like Iran have the national ISP market under their thumb. PA: There needs to be a way to deal out proxies to clients without the ability to easily reveal the entire network to anyone. Perhaps even semi-static assignments similar to DHCP. Of course, there is also the problem of 'blocking the dealer' similar to the P2P security issues with trackers. Ultimately, to really make this fool proof, there would need to be a way to communicate proxy dealers offline (verbally / off-network) in a concealable way. Q: How can we address bad guys blocking port 443. PA: Proxies should be able to hide behind other services such as 25,80,110. Also nice would be a 'spoof greeting' feature that would simulate a 'normal' service for that port before a magic code was sent. Of course, the magic code would need to be changeable (possibly dynamically by a proxy dealer). Q: What about DPI which can provide encryption protocol info to the bad guys (if not the payload). PA: plug-in packet obfuscation, possibly agreed upon between proxy and dealer and embedded in a magic code given by the dealer to the client then provided back to the proxy in the request header. This could be implemented by means of a tiny secure VM that ran small byte-code obfuscator programs shared between proxy and dealer and referenced by the magic code. Even though the bad guys could run the VM de-obfuscator, it would be challenging to implement at OSI levels 1-4 given current technology. The ultimate idea would be to keep the Bad Guys busy chasing their tails and break them through over investment in competence. As they attempt to keep up with the changing methodologies they become victims of their own system of control, meanwhile they have less time to do their normal bad guy stuff. Basically, the circumvention tool itself becomes an agent provocateur. --dbenn...@bensoft.com *********************************************************************** To unsubscribe, send an e-mail to majord...@torproject.org with unsubscribe or-talk in the body. http://archives.seul.org/or/talk/