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Making Data Unvanish

Posted by kdawson on from the sybil-attack dept.

sertsa writes "Earlier this year a group of researchers at the University of Washington came up with a scheme to use peer-to-peer networks to store and, ultimately, to forget the keys for encrypted messages, causing them to 'Vanish.' Now a group from researchers from UT Austin, Princeton, and the University of Michigan has come up with a way to break this approach, by making a single computer appear to be many nodes on the p2p network. 'In our experiments with Unvanish, we have shown that it is possible to make Vanish messages reappear long after they should have disappeared nearly 100 percent of the time...'"

5 of 34 comments (clear)

  1. Vanishing is impossible to get by sopssa · · Score: 5, Insightful

    In my opinion Vanish didn't really serve any purpose.

    - As we all know (and what MPAA/RIIA hate), once you've got hold of the data you cannot "vanish" it. It's really easy to save a copy of it.
    - If you wanted encryption with public/private keys, theres PGP and other solutions to do it.

    So the only thing Vanish added was the impossible-to-archieve vanishing of data.

    Along with that it distributes your secret content all over the p2p network, where one machine can act as thousands of clients like to article says. I'd rather skip that and send the message directly and tell the other party to delete it, because vanishing doens't work if both parties dont do it.

  2. Sparring by spydabyte · · Score: 4, Interesting
    They certainly are sparring, see the University of Washington response:

    Update, 9/20/2009: Other researchers have recently discovered a vulnerability in our original Vanish research prototype. Their work shows that the Vuze DHT on which we built the original prototype did not provide sufficient security properties, and that there are therefore attacks that can capture Vanish keys. We released a revised prototype on September 20, 2009. This revised prototype, which distributes keys across both the Vuze DHT and OpenDHT, invalidates this attack. In addition, we are working to further strengthen Vanish from two angles: (1) by hardening the underlying DHT for Vanish-like purposes and (2) by modifying applications to make more intelligent use of DHTs. Please see our new technical report for additional information about the currently known attacks and our defenses. Due to the complexity of the systems we are relying upon, we would like to strengthen our advice that users should be cautious if they want to use Vanish. At this point, Vanish should only be used for experimental purposes. We do encourage researchers, however, to analyze it and improve upon it.

    1. Re:Sparring by vlm · · Score: 3, Interesting

      But does this *really* invalidate this type of attack? It seems it just adds another p2p protocol on it, and it would still be as vulnerable as before. Only difference seems to be that the current tool just doesn't work at the moment. Approach would still be the same.

      I think the UW folks are reading slashdot and editing their page as we speak. The page now includes the quote:

      This revised prototype, which distributes keys across both the Vuze DHT and OpenDHT, invalidates this attack. This is because OpenDHT has a closed-access model as opposed to an open-access model like Vuze, which is what drives the current attack. In addition, we are working to further strengthen Vanish from two angles:

      So, Vanish people, I know you're listening, please respond to my being unclear how a closed-access model prevents the attack as opposed to just makes it a wee bit harder for small weak opponents, not so much impact to bigger ones.

      --
      "Science flies us to the moon. Religion flies us into buildings." - Victor Stenger
  3. Like DRM by bzzfzz · · Score: 5, Insightful

    Any kind of security system that provides a limited lifetime or constrained redistribution rights for messages is, fundamentally, DRM. Therefore, it's subject to the same kinds of attacks that cause DRM to fail. Ultimately, unless you can build a trusted platform module with remote attestation that is tamper proof, there are gaps. This particular attack is, at a more abstract level, really about producing counterfeit trusted nodes. Without a TPM at each node and some way to authenticate independence through a trust hierarchy, there's no way for this to work.

  4. Orange book... by NCamero · · Score: 3, Informative

    Orange book:

    A-
    You are are a single communication construct. No one outside the circle of trust has any idea what is communicated.

    B-
    You are in a network (circle) of trust. moving data to each other is logged, and allowed/censored.

    C-
    A typical LAN with verifiable security.

    D-
    The internet, a net work of networks. Data can 'vanish', as a function of time/money spent on keeping the data stored.

    Read the data security handbook summarized:
    http://en.wikipedia.org/wiki/Trusted_Computer_System_Evaluation_Criteria