[Ndn-interest] NDN protocol principles: no privacy?

[Marc.Mosko at parc.com]

> On Mar 14, 2016, at 8:44 PM, Tai-Lin Chu <tailinchu at gmail.com> wrote:
> 
>> sure - I don't want to expose names that identify me, or expose my communication activities. given that, the "network" doesn't have the job of finding things for me by partial names - I only want to expose the details of my communication to a service that I have authenticated, and only when those details are encrypted. the "names" visible to the network in that sort of world just get the packets moving - and the only LPM needed is LPM in the FIB to get me to one or more instances of a service.
> 
> Immutability is related to in-network discovery with LPM.  If all packets are immutable, and there is no in-network discovery, ndn must rely on some other protocol that cannot not build on top of ndn for discovery (we should all agree that randomly guessing a version number or a certain name is not going to work well as “discovery”). This devalues ndn as an “universal" protocol.

Could you please define immutable?  Do you mean that a single publisher will never use the same name for different contents?  Is that mandatory or enforceable?  Or do you mean that there is some cryptographic function possible on a packet such that one can detect if it changes?  Are those cryptographic primitives mandatory in each packet?

I disagree that it is a necessary condition that one have name suffix completion matching of a data object to an interest to facilitate discovery.  One can build a discovery protocol over exact name matching.  I usually build these where the cache returns a chunked table of contents listing possible matches instead of the CCNx 0.x / NDN approach of having to return a (potentially very large) data object and walk a tree which is really only efficient if you expect what you want to be left-most or right-most child and not require iteration.


> 
> 
>> On Mar 14, 2016, at 12:10 PM, Mark Stapp <mjs at cisco.com> wrote:
>> 
>> interesting -
>> 
>> On 3/14/16 11:27 AM, Burke, Jeff wrote:
>>> 
>> [...]
>> RFC 6973 takes a nice approach, for example, by offering
>>>> definitions of some technical properties and mechanisms, but not trying
>>>> to formulate an overall definition of "privacy".
>>> 
>>> So I can try to understand your point here - do you agree with the
>> authors that the primary privacy concerns are those of individuals? (Or,
>> more generally, are corporations people here for this discussion - a
>> more generic "data owner"?)
>>> 
>> 
>> hmm - well, I don't think corporations are people, in the citizens united sense, but I think there's lots of commercial communication that needs to have the best possible protection, whether it's B2C or B2B?
>> 
>>>> The editors there say
>>>> that the body of the document, the discussion of the tradeoffs and
>>>> alternatives, is the best way they could come up with to approach that
>>>> abstraction. in practical terms, as you know well I think there's been
>>>> an over-reliance on opportunistic caching in ICN generally, and as a
>>>> result observability and correlation are defined to be positive
>>>> properties of ICN communication rather than harmful ones.
>>> 
>>> 
>>> Would I be correct to parse your concerns into two pieces that may
>> have different implications:
>>> 
>>> - Confidentiality of request (e.g., the consumer side)
>>> - Confidentiality of publication (e.g., the publisher side)
>>> 
>> 
>> I think I have a mental image of "confidential request" - where an observer cannot see much beyond the routeable prefix needed to reach an instance of the service I want to communicate with. I'm not sure what "confidential publication" means, though? I think I want the replies to my requests to be encrypted with ephemeral, forward-secure key material, I don't want the names in the replies to expose any more than the names in the requests, and I want to be able to authenticate the service before I expose anything about my own identity or intentions. is that what you meant by "the publisher side"?
>> 
>> [...]
>> 
>>>> 
>>>> most of these six "principles" sounded like "mechanisms" to me - the
>>>> list felt like the end of a discussion about alternatives and the best
>>>> ways to implement an architecture, rather than the start of one. it
>>>> sounded like "we're tired of questions about LPM in the PIT, so we're
>>>> going to stop calling that a possible mechanism and start calling it an
>>>> inevitable, immutable, unquestionable 'principle'".
>>> 
>>> Well, to take LPM for an example - it's actually not mentioned in
>>> the
>> principle doc that Alex sent. The principle I suspect that you are
>> referring to is:
>>> 
>>> [5] In-Network Name Discovery: Interests should be able use
>>> incomplete
>> names to retrieve data packets.
>>> A consumer may not know the complete network-level name for data, as
>> some parts of the name cannot be guessed, computed, or inferred
>> beforehand. Once initial data is received, naming conventions can help
>> determine complete names of other related data:
>>> 
>>> 
>>> * majority of interests will carry complete names
>>> 
>>> * in-network name discovery expected to be used to bootstrap
>> communication)
>>> 
>>> 
>>> 
>>> Can you explain your objection in these terms?
>>> 
>> 
>> sure - I don't want to expose names that identify me, or expose my communication activities. given that, the "network" doesn't have the job of finding things for me by partial names - I only want to expose the details of my communication to a service that I have authenticated, and only when those details are encrypted. the "names" visible to the network in that sort of world just get the packets moving - and the only LPM needed is LPM in the FIB to get me to one or more instances of a service.
>> 
>> Thanks,
>> Mark
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> 
> 
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