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Jeeves – A Language for Automatically Enforcing Privacy Policies

projects.csail.mit.edu

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Re: Jeeves – A Language for Automatically Enforcing Privacy Policies

#31

@jeanyang - This is really amazing work, and I'm very interested in it. One question for you: On slide 10 you show "state of the art" as a bunch of conditional logic guarding the returned values and "Jeeves" as just a simple properly lookup. Do you know if Facebook's "state of the art" is as you are describing it in this slide, or do you think they have a proprietary framework similar to Jeeves that they use internal…

Thanks for your interest! This is a great question. I've worked at Facebook on backend privacy, so let me think about what I can say without violating my NDA.

It's my understanding that large companies will create proprietary frameworks that help manage privacy policies on data. Programmers will typically be required to follow certain coding discipline when working with sensitive values so that they're calling library functions to manage policies. To my knowledge, however, these libraries deal with access control (who can access a specific piece of information) rather than information flow (how information may flow through a system).

Now here's the difference between access control and information flow--and why we need a language (or at least a DSL). When you only have access control, you're trusting the programmer to tell you correctly at one point where a piece of data is going. Even if a sensitive location value is used in a bunch of search queries, the result of which is shared as a status (that becomes visible to many people with different levels of access), the programmer is responsible for asking for the right level of access when accessing that location. With the complex policies we're starting to see in modern applications, managing this is becoming increasingly burdensome for developers. That's why were looking at how to automatically handle information flow: the system tracks how sensitive values are used in order to make sure the values--and resulting computations--are flowing only to those with appropriate permissions. While it's relatively simple to hook access control into existing programming models, automatically handling information flow requires enhancing the language semantics (especially for conditions and function calls) to track additional information.

Automatically managing information flow the way Jeeves does significantly relieves programmer burden, but can be computationally expensive. Much of our research these days is about how to make this more efficient so that companies can one day put this sort of mechanism into their production systems.

Happy to answer additional questions!

Re: Jeeves – A Language for Automatically Enforcing Privacy Policies

#32

Earlier quoted context omitted.

Can you give a high-level overview of the implementation? I read the README, and if I could guess it seems enforcement is determined through wrapped values, lambda functions that determine access based on numeric thresholds, and roles are assigned numbers in that range. Is that close?

Yes, pretty close. In Jeeves, sensitive values are essentially pairs of values guarded by a label: , where k is the label, vHigh is the high-confidentiality "view" (corresponding to, for instance, my sensitive GPS location), and vLow is the low-confidentiality "view" (corresponding to, for instance, some coarser-grained version of my location--such as what country I'm in). Rather than roles, we have these flexible po…

Thanks for the detailed reply!

Re: Jeeves – A Language for Automatically Enforcing Privacy Policies

#33

@jeanyang - This is really amazing work, and I'm very interested in it. One question for you: On slide 10 you show "state of the art" as a bunch of conditional logic guarding the returned values and "Jeeves" as just a simple properly lookup. Do you know if Facebook's "state of the art" is as you are describing it in this slide, or do you think they have a proprietary framework similar to Jeeves that they use internal…

Thanks for your interest! This is a great question. I've worked at Facebook on backend privacy, so let me think about what I can say without violating my NDA. It's my understanding that large companies will create proprietary frameworks that help manage privacy policies on data. Programmers will typically be required to follow certain coding discipline when working with sensitive values so that they're calling librar…

@jeanyang - Thanks, this is a terrific answer!

"When you only have access control, you're trusting the programmer to tell you correctly at one point where a piece of data is going."

Right, that pretty much sums it all up, and I have my suspicions (independent of your response) that something like Jeeves could add value even to a "state of the art" company like Facebook :)

I'll be watching your project with great interest and may even follow up with you "offline" once I dig in some more, because I think you're really onto something of great importance. Any sufficiently complex enterprise system eventually needs something not too different from what you're working on here...

Re: Jeeves – A Language for Automatically Enforcing Privacy Policies

#35
post #9
post #8

From the papers section: "A Language for Automatically Enforcing Privacy Policies" http://projects.csail.mit.edu/jeeves/papers/popl088-yang.pdf (I hope you like the lambda calculus!)

This is a better (video) introduction for programmers: http://projects.csail.mit.edu/jeeves/talks.php

This paper is the most up-to-date on the semantics of the current implementation: http://projects.csail.mit.edu/jeeves/papers/plas07-austin.pd...

Re: Jeeves – A Language for Automatically Enforcing Privacy Policies

#36
post #34

It's not a programming language, but a DSL.

Please explain the difference.

A language exists on its own, with its own syntax and semantics. It may interoperate with other languages, but it usually takes some work to get a language written in one language to talk to a language executing in another language. (Examples include C/OCaml and all the languages that execute on the .NET runtime.)

An embedded domain-specific language is a language with its own semantics that has been grafted onto another language. For instance, Jeeves is embedded in Python. We can use Jeeves as a Python library, but when we're using Jeeves functions, the program behave like Jeeves programs rather than vanilla Python programs. (In this case, it means that the runtime tracks different possible views of sensitive values and computations done on them.) When programmers use the @jeeves decorator and the Jeeves API, the programs look like Python programs and can even use Python built-in functions and libraries, but the Jeeves library is doing work behind the scenes to make the programs behave differently.

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