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The larger issue is that you now have to push key management to the user, and the support problems that go with that. Key management is hard and painful. Tell

The larger issue is that you now have to push key management to the user, and the support problems that go with that. Key management is hard and painful. Telling a customer that they can't access their data on your service because they broke their laptop is going to make them very unhappy. Otherwise, there'd be plenty of services competing with Drive, DropBox, etc, that did just that.

pdkl95 11y ago
> push key management to the user There is no other way. Unfortunately, there has been a serious lack of r&d in this area, so we have a lot of catching up to do. I believe it can be made to work, though, because this is not entirely a new idea for most people: they already understand physical keys and the problems associated with losing them. Moving to digital (public-)keys isn't a perfect match, but it is entirely possible to leverage the skills and experience that people already have. For example, contrary to the advice used a decade ago, Schneier recommends[1] that people write down their passwords (avoiding the memorization problem). This can provide good enough security most of the time, because people already understand how to provide security for their wallet. Incidentally, I always liked the basic idea of the Java Ring[2]. It was basically a fancy (for the time) smart card, but the idea of storing the chip in a ring is an attempt to make security management personal, which is an idea that had potential. [1] https://www.schneier.com/blog/archives/2005/06/write_down_your.html https://www.schneier.com/blog/archives/2005/06/write_down_yo... [2] http://www.javaworld.com/article/2076641/learn-java/an-introduction-to-the-java-ring.html http://www.javaworld.com/article/2076641/learn-java/an-intro... edit: forgot a link
- NoGravitas 11y ago
  I generally agree with you, but there's one problem with the physical key analogy. The security of physical keys is weak enough that there's always a fallback if you lose all the copies of your key: you pay a locksmith to come pick the lock and rekey it. You can't do this with digital keys because a digital key that is weak enough for this strategy to be usable is also too weak to protect you from the main class of attacks it's supposed to be protecting you from.
  - gioele 11y ago
    > there's always a fallback if you lose all the copies of your key: you pay a locksmith to come pick the lock and rekey it. In the digital world you have Shamir's Secret Sharing. Generate a non-encrypting, non-signing, decode-only key and give a N-th of if to N escrow services. If you lose your key you contact M of those entities and recover the data. Plenty of tricks have been created in the last two decades to address the problems associated with key ownership, the problem is always the lack of UI and of standardization in general.
    - whopa 11y ago
      These escrow services would be centralized targets too just like Microsoft, Google, Amazon, etc.
      - morninj 11y ago
        I think the idea is that you store only part of the key with each service, and you're the only one who knows which services have which parts--so, you're the only one who can reconstruct the key. Of course, the UI is still a problem.
    - mjevans 11y ago
      Who says you need escrow services for that? Store your N'th fragments with /friends and family/ that you know well. You might also be able to get in on distributed backups together.
      - tajen 11y ago
        Here comes Facebook Key Escrow?
    - NoGravitas 11y ago
      Thanks. I did not know that.
  - pdkl95 11y ago
    Sure, as I mentioned, the physical key analogy isn't a perfect match. I'm jsut suggesting that there are some clear starting places where it should be possible to leverage existing skills, instead of starting from scratch. The details about a actually-usable product will be more complicated (and probably requires some experimentation).
- deleted 11y ago
  [deleted]
- amelius 11y ago
  I guess that Ring can be replaced by a Smartphone or a Smartwatch.
- whopa 11y ago
  People do lose their physical keys though. And in pretty much all cases, there is a recovery mechanism to get at whatever the physical keys are protecting. This may involve drilling a hole or the like, but there is a fallback. With any digital crypto worth using, there is no recovery mechanism.
- kbenson 11y ago
  > There is no other way. Well, we can always legislate. Even with encryption of data, you want legislation. Without legislation, the Government will just create a separate channel for data collection to bypass your encryption. It starts unencrypted at the remote site, so it's not that hard to do. Even with legislation there will be problems, and overstepping, but at least then there's some semblance of recourse and ways to fight. You can't fix the problem for everyone and always, but you can fix it for most people most the time. This is the sort of thing that should be in trade agreements and treaties.
LordKano 11y ago
Telling a customer that they can't access their data on your service because they broke their laptop is going to make them very unhappy. Depending on your target market, that can be a selling point. Tell them early and tell them often that you don't keep copies of their keys and if they lose them, they won't be able to access the information. Remind them to make backups.

pdkl95 11y ago

> push key management to the user There is no other way. Unfortunately, there has been a serious lack of r&d in this area, so we have a lot of catching up to do. I believe it can be made to work, though, because this is not entirely a new idea for most people: they already understand physical keys and the problems associated with losing them. Moving to digital (public-)keys isn't a perfect match, but it is entirely possible to leverage the skills and experience that people already have. For example, contrary to the advice used a decade ago, Schneier recommends[1] that people write down their passwords (avoiding the memorization problem). This can provide good enough security most of the time, because people already understand how to provide security for their wallet. Incidentally, I always liked the basic idea of the Java Ring[2]. It was basically a fancy (for the time) smart card, but the idea of storing the chip in a ring is an attempt to make security management personal, which is an idea that had potential. [1] https://www.schneier.com/blog/archives/2005/06/write_down_your.html https://www.schneier.com/blog/archives/2005/06/write_down_yo... [2] http://www.javaworld.com/article/2076641/learn-java/an-introduction-to-the-java-ring.html http://www.javaworld.com/article/2076641/learn-java/an-intro... edit: forgot a link

NoGravitas 11y ago
I generally agree with you, but there's one problem with the physical key analogy. The security of physical keys is weak enough that there's always a fallback if you lose all the copies of your key: you pay a locksmith to come pick the lock and rekey it. You can't do this with digital keys because a digital key that is weak enough for this strategy to be usable is also too weak to protect you from the main class of attacks it's supposed to be protecting you from.
- gioele 11y ago
  > there's always a fallback if you lose all the copies of your key: you pay a locksmith to come pick the lock and rekey it. In the digital world you have Shamir's Secret Sharing. Generate a non-encrypting, non-signing, decode-only key and give a N-th of if to N escrow services. If you lose your key you contact M of those entities and recover the data. Plenty of tricks have been created in the last two decades to address the problems associated with key ownership, the problem is always the lack of UI and of standardization in general.
  - whopa 11y ago
    These escrow services would be centralized targets too just like Microsoft, Google, Amazon, etc.
    - morninj 11y ago
      I think the idea is that you store only part of the key with each service, and you're the only one who knows which services have which parts--so, you're the only one who can reconstruct the key. Of course, the UI is still a problem.
  - mjevans 11y ago
    Who says you need escrow services for that? Store your N'th fragments with /friends and family/ that you know well. You might also be able to get in on distributed backups together.
    - tajen 11y ago
      Here comes Facebook Key Escrow?
  - NoGravitas 11y ago
    Thanks. I did not know that.
- pdkl95 11y ago
  Sure, as I mentioned, the physical key analogy isn't a perfect match. I'm jsut suggesting that there are some clear starting places where it should be possible to leverage existing skills, instead of starting from scratch. The details about a actually-usable product will be more complicated (and probably requires some experimentation).
deleted 11y ago
[deleted]
amelius 11y ago
I guess that Ring can be replaced by a Smartphone or a Smartwatch.
whopa 11y ago
People do lose their physical keys though. And in pretty much all cases, there is a recovery mechanism to get at whatever the physical keys are protecting. This may involve drilling a hole or the like, but there is a fallback. With any digital crypto worth using, there is no recovery mechanism.
kbenson 11y ago
> There is no other way. Well, we can always legislate. Even with encryption of data, you want legislation. Without legislation, the Government will just create a separate channel for data collection to bypass your encryption. It starts unencrypted at the remote site, so it's not that hard to do. Even with legislation there will be problems, and overstepping, but at least then there's some semblance of recourse and ways to fight. You can't fix the problem for everyone and always, but you can fix it for most people most the time. This is the sort of thing that should be in trade agreements and treaties.

LordKano 11y ago

Telling a customer that they can't access their data on your service because they broke their laptop is going to make them very unhappy. Depending on your target market, that can be a selling point. Tell them early and tell them often that you don't keep copies of their keys and if they lose them, they won't be able to access the information. Remind them to make backups.