Berners-Lee - Distributed Social Networking
MIT CSAIL DIG

Distributed Social Networking

Through

Socially Aware Cloud Storage

Tim Berners-Lee, <timbl@w3.org>

DIG Group in CSAIL

Social Network Silos

Social Network Silos - 2

Linked Open Data

Read-only Linked Open Data Cloud 2011

richard.cyganiak.de 2011 Data: CKAN

Breaking the silos

Building Apps

A responsible system

Build on existing CSAIL/DIG work

• System allows privacy to be respected
• Allow users to do the right thing with data
• Not just lock-down by access control
• Allows accountability - how was data used
• Carry metadata - licences, rights (not DRM)

Much of this may need new protocols

Opportunity

• Break down the silos
• Benefits of user's data being usable by user.
• Market for open Apps explodes
• Increase innovation among developers and users

Technology

• Authentication: WebID- FOAF+SSL
• Authorization: RDF
• WebDAV
• SPARQL Update
• Widget libraries
• Application Builders

AC resources on the web

• Access control files are linked data.
• Access to ACFs for a resource is not recursively given by an ACF for the ACF: instead, one must have "Control" access to the original resource.
• An ontology for access control exists.
• Access control files can be edited just as other writable linked data.
• Access control files for a resource are discovered by a client using the HTTP link header.

Web Groups

• Identified by an http: URI
• Anyone can make one
• You can refer to any group anywhere
• If you look up the URI you get a list of members of the group (RDFS Class)
• Members are referred to by WebIDs. (URIs)
• You could get some RDFS, like a subclass statement

Authorization

1. The server reads the ACF (or consults a cache.) If the ACF gives public access to the operation required, it allows it.
2. It puts the client through an foaf+ssl challenge if it is not already authenticated.
3. If access is allowed to some but it is not obvious whether the current requester is allowed, the URIs in the ACL are dereferenced, if necessary recursively. For example a class mentioned is dereferenced it will typically return a list of members of the class.

Server Side Implementations

Sparql-Update:

Plus any WebDAV implementaion

Issues

• Enforcing protocols
• Extending protocols
• Security in general
• Access control model - choice of complexity

Conclusion

• This is just Webizing unix file system
• Building on existing technologies
• Open App market should follow
• Commodity pricing of cloud storage should follow
• Interoperable standards essential