Digital Object Architecture: an Advanced Architecture for Managing Digital Information

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 -- 128 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
Digital Object Architecture
User
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
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
ltinput sequencegtltH1gt ltH2gt ltParamsgt ltoutput
sequencegt 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
Federation Level Metadata
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
• 10.1234/Conf_Summary
• HDL10.1234/Conf_ Summary
• hdl.handle.net/10.1234/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

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Resolution Mechanism
Multiple Workstations Distributed Globally
DO Identifier Resolution Record
Handle System ltwww.handle.netgt
System is non nodal Scaleable
Distributed Supports global (and local) resolution
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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
GHR
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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
?
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Planned Deployment of aMulti-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.