1. Digital Object Architecture: an Advanced Architecture for Managing Digital Information
WSIS Forum 2011
May 19, 2011
Presentation by
Robert E. Kahn
President & CEO
Corporation for National Research Initiatives

2. Origins of the Internet
Multiple Different Packet Networks
Open Architecture
Implemented via the TCP/IP Protocols
Standards Processes
Sustained Research Support
Eventually resulting in
Commercialization
Widespread Dissemination
Global Acceptance

3. Three Initial Networks
DARPA originally funded three seminal packet networks – ARPANET, Packet Radio, Packet Satellite
The Internet came about from a desire to enable users and their computers to communicate efficiently, independent of the network they were using
Initial challenges were in areas such as:
Addressing
Routing
Congestion Control
Host Protocols
Addressing (16 bits to the wire, 32 bit IPv4 addresses; later bit IPv6 addresses, URLs)

4. Key Initial Decisions
Global Addresses (IP) freed us from ARPANET addressing of the wires
Gateways introduced for IP routing and for Network “Impedance Matching” – now called routers
TCP dealt with network-related concerns
different packet sizes, duplicates, error detection, losses due to tunnels, mountains, jamming, etc.
Enabled separate network administration
Global information system based on an open architecture

5. From Packet Communication to Information Management
The Internet did not start out with a primary goal of assisting users in managing information.
Fast, efficient, reliable, global connectivity was the main goal
Information management was limited to ensuring proper information flows in the Internet
The World Wide Web was an important step in simplifying user access to information
Other alternatives are now emerging.
We now present an open architecture approach to information management that
Makes use of existing Internet capabilities
allows different types of information management systems to be developed and interoperate.

6. Digital Object Architecture
To reformulate the Internet architecture to focus more specifically on managing information rather than just communicating bits
Making use of its world-wide connectivity, but independent of current technology choices
Enabling existing and new types of information to be reliably managed and accessed in the Internet environment, including over very long periods of time
Providing mechanisms to stimulate dynamic new forms of expression and to manifest older forms
Support for multi-lingual identifier names in most native/local scripts
While supporting privacy, security, intellectual property protection, managed access and well-formed business practices

7. Digital Object Architecture
Technical Components
Digital Objects (DOs)
Structured data with a unique persistent identifier
Resolution of the Unique Identifiers
To “state information” about the DOs
Repositories
To deposit DOs
To access DOs with security
Registries
To create and store metadata
For secure searching

8. Repositories / Collections
Digital Object Architecture
Repositories / Collections
Client
User
Resolution System
Resource Discovery
Metadata Registries
in lieu of traditional
Search Engines
Metadata Databases
Catalogues, Guides, etc.

9. Selected Digital Object Types
Documents, Books, Music, Videos, Spreadsheets
Personal data (coordinates, financial, medical)
Observational data (climate, radio astronomy)
Networking Information (operations, provisioning, forecasting)
Commerce and Business Information (contracts, bills of lading, letters of credit, etc)
Software (programs, running processes & distributed systems)
Information about “Things”

10. Any Hardware & Software
Repositories
Store and Access Digital Objects on the Net
Logical External Interface
Any Hardware & Software
Configuration
Digital Object
Protocol

11. Digital Object Protocol
Uniform interface for accessing repositories and their digital objects
Based on the use of identifiers
Provides authentication of both users and servers upon request or where required
Uses identity management based on the use of public keys
Key means of implementing interoperability

12. The Digital Object Protocol is a Meta-Level, Extensible Interface
<input sequence><H1> <H2> <Params> <output sequence>
H1 is a handle for the operation applied to the Target DO H2.
Similarly both A and B are known by their Handles HA and HB.
The steps of the protocol are:
Establish a connection from A to B
{Optionally} A asks B to authenticate himself
If successful, A provides an input string to B
{Optionally} B asks A to authenticate herself
B provides the results of the operation
Either party may choose to continue or close

13. Metadata Registry
Registers the existence and access conditions for Digital Objects
Enables collections to be defined with appropriate access controls
Provides a user interface to browse and search the registry, and an API for other programs to search the registry
Integrates existing technologies
Handle System for identification and access
Digital Object Repository for metadata object storage and access
XML for object description and submission
Specification of Metadata Schemas

14. CORDRA CORDRA Community Registry Master Registry of Registries
Content
Repositories
CORDRA
Community
Registry
Intermediate
of Registries
Federation
Level
Metadata
CORDRA
Community
Registry
Content
Repositories
Intermediate
of Registries
Federation Level
Metadata
Master
Registry
of Registries
Federation Level
Metadata
CORDRA
Registry
CORDRA
Registry
Community
Content
Repositories

15. What are Handles? Why Resolution Systems?
CNRI uses the name “Handles” to denote digital object identifiers
Others may prefer to use their own descriptors
Existing identifier schemes are accommodated
Identifiers provide a way to identify data structures independent of their physical form or location, if any
Identifiers can be of many forms, and may contain randomly generated strings, date-time stamps as well as semantics
The identifier itself will not usually contain useful information about the digital object
The resolution system is intended to make available the useful information

16. Why are identifiers Important
For global addressing
and possibly routing
For long-term information preservation
For building linkages
In lieu of attachments
To create virtual structures
For accessing related metadata
To convey search results
To authenticate/validate
Connectivity
Individual Digital Objects
Identity

17. Structure of the Identifiers
Digital Object Identifiers are structured as “prefix/suffix”
They may be conveyed in various forms, such as:
/Conf_Summary
HDL: /Conf_ Summary
hdl.handle.net/ /Conf_Summary
Each prefix has its own administrator with PKI access to the system for creation, change and deletion.
Resolution of an identifier results in a returned resolution record – generally within a fraction of a second

18. Multiple Workstations
Resolution Mechanism
Multiple Workstations
Distributed Globally
DO Identifier
Resolution
Record
Handle System
<
System is non –nodal
Scaleable & Distributed
Supports global (and local) resolution

19. Handle System Features
Supports both Resolution and Administration
Internationalized character sets
Secured resolution service
Provides for Unique Persistent Identifiers
Current Users include:
DOI System, Open Archives Initiative, Library of Congress, CNNIC, Office of European Publications, DataCite, EIDR, DSpace Community and others

20. Handle Resolution The Handle System is a collection of
handle services,
Client
GHR
LHS
each of which
consists of one or
more replicated sites,
Site 1
Site 2
Site 3
…...
Site n
each of which may
have one or more
servers.
/abc
URL 4 8 #1 #2 #n #4 #3
...

21. Mirroring the Global Handle Registry
Administration M M P M M
• • • •
• • • •
Contains System
Handle Records
user
user
user
Non-System Handle Records
are in lots of Local Handle Services 

22. Planned Deployment of a Multi-Primary Global Registry
A limited number of primaries
each Administered Separately
Plus Mirrors
Plus Mirrors P P P P P
• • • •
• • • •
Contains System
Handle Records
user
user
user
Non-System Handle Records
are in lots of Local Handle Services 

23. Observations
Identifiers provide the glue that holds complex distributed systems together
Security can be provided at a very fine level of granularity in the system
Repositories enable reliable long-term access to digital objects over generations of technology change
Registries enable digital objects to be made known and findable using multiple metadata schemas
The Multi-primary Global Registry enables distributed administration on a collaborative basis by multiple parties around the world.
Finally, DONA will provide a framework for the management of the DO Architecture in the future.