Drummond Reed, Chief Trust Officer at Evernym, will explain in our second Webinar "Decentralized Identifiers (DIDs) - Building Block of Self-Sovereign Identity (SSI)" giving us the background on how DIDs work, where they come from and why they are important for Blockchain based Digital Identity.

1. Webinar: Decentralized Identifiers (DIDs)
The Fundamental Building Block of Self-Sovereign Identity
(SSI)
SSIMeetup.org07 May 2018
Drummond Reed
Chief Trust Officer Evernym and Sovrin Foundation Trustee
@drummondreed
https://creativecommons.org/licenses/by-sa/4.0/

2. 1. Empower global SSI communities
2. Open to everyone interested in SSI
3. All content is shared with CC BY SA
SSIMeetup.org
Alex Preukschat @SSIMeetup @AlexPreukschat
Coordinating Node SSIMeetup.org
https://creativecommons.org/licenses/by-sa/4.0/
SSIMeetup objectives
07 May 2018

3. Who Am I?
3
• 20 years in Internet Identity
• 13 years (all 26 instances) of
Internet Identity Workshop
• 15 years in Internet Identity
standards
– W3C
– OASIS
– IETF
– OpenID Foundation
Years

4. Who Am I?
4
Chief Trust Officer, Evernym
Trustee, Sovrin Foundation
Chair, Sovrin Trust Framework
Co-Chair, Decentralized
Identity Foundation ID WG
Co-Chair, OASIS XDI TC
Principle Investigator, U.S
Dept. of Homeland Security
DID and DKMS Projects
Hats

5. Three Models of
Digital Identity

6. #1: Siloed (Centralized) Identity
Standards:
SSIMeetup.org

7. #2: Third-Party IDP (Federated) Identity
Standards:
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8. #3: Self-Sovereign Identity (SSI)
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9. #3: Self-Sovereign Identity (SSI)
Digital
wallet
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10. Emerging Open Standards for SSI
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11. What is a DID?

12. 078-05-1120
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13. did:sov:3k9dg356wdcj5gf2k9bw8kfg7a
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14. 14
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15. 15
You will not have just one DID.
You will have thousands.
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16. 16
Each one will give you a
lifetime encrypted private channel
with another person, organization,
or thing
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17. 17
You will use it not just for
authentication, but to exchange
verifiable digital credentials
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18. 18
Best of all: there is
no central registration authority—
every DID is registered directly by
you on a public or private
blockchain or distributed network
SSIMeetup.org

19. In summary, a DID is…
A permanent (persistent) identifier
– It never needs to change
A resolvable identifier
– You can look it up to get metadata
A cryptographically-verifiable identifier
– You can prove ownership using cryptography
A decentralized identifier
– No centralized registration authority is required
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20. 20
No identifier in history has had all
four of these properties—because
what fundamentally enables DIDs is
blockchain technology
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21. What does a DID
look like?

22. URN Syntax (RFC 2141)
22
urn:uuid:ae84-d5c2-9fb785ea-72cd34
Namespace
Scheme
Namespace-Specific Identifier
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23. 23
did:sov:3k9dg356wdcj5gf2k9bw8kfg7a
Method
Scheme
Method-Specific Identifier
DID Syntax (W3C)
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24. What is a DID
method spec?

25. 25
A DID method specification
defines how to read and write
a DID (and its DID document)
on a specific blockchain or
distributed network
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26. 26
Active DID Method Specs

27. The syntax of the method-specific identifier
Any method-specific elements of a
DID document
The CRUD (Create, Read, Update, Delete)
operations on DIDs and DID documents for
the target system
27
A DID Method spec defines…
SSIMeetup.org

28. What is a DID
document?

29. 29
{ “Key”: “Value” }
SSIMeetup.org

30. DID (for self-description)
Set of public keys (for verification)
Set of auth methods (for authentication)
Set of service endpoints (for interaction)
Timestamp (for audit history)
Signature (for integrity)
30
The standard elements of a DID doc
SSIMeetup.org

31. {
"@context": "https://w3id.org/did/v1",
"id": "did:example:123456789abcdefghi",
"publicKey": [{
"id": "did:example:123456789abcdefghi#keys-1",
"type": "RsaSigningKey2018",
"owner": "did:example:123456789abcdefghi",
"publicKeyPem": "-----BEGIN PUBLIC KEY...END PUBLIC KEY-----rn"
}],
"authentication": [{
"type": "RsaSignatureAuthentication2018",
"publicKey": "did:example:123456789abcdefghi#keys-1"
}],
"service": [{
"type": "ExampleService",
"serviceEndpoint": "https://example.com/endpoint/8377464"
}],
Example DID Document (Part 1)
31
SSIMeetup.org

32. Example DID Document (Part 2)
32
"created": "2002-10-10T17:00:00Z",
"updated": "2016-10-17T02:41:00Z",
"signature": {
"type": "RsaSignature2016",
"created": "2016-02-08T16:02:20Z",
"creator": "did:sov:8uQhQMGzWxR8vw5P3UWH1j#key/1",
"signatureValue": "IOmA4R7TfhkYTYW87z640O3GYFldw0
yqie9Wl1kZ5OBYNAKOwG5uOsPRK8/2C4STOWF+83cMcbZ3CBMq2/
gi25s="
}
}
SSIMeetup.org

33. DID paths, queries, fragments
• A DID itself always identifies a person, organization, or
thing
• But like any URI, a DID may be followed by a path,
query, and/or fragment
• A DID without a path or query but with a fragment is a
pointer into the DID document
• A DID with a path identifies another resource “rooted”
on the DID
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34. DIDs and
Decentralized Identity

35. 35
DIDs only represent the very
bottom layer of the
decentralized identity stack
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36. DID Layer
The decentralized identity “stack”
Cloud Layer
Identity Owners
Edge Layer
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37. DIDs enable digitally signed verifiable claims
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38. DID Standardization

39. How did DIDs happen?
Conceived in 2015 by W3C Verifiable Claims Task
Force
Evernym applied to U.S. Dept of Homeland Security
S&T to fund DID standard
Over 2016 Evernym worked with SSI community to
develop DID V1.0
June 2017 DID spec contributed to W3C Credentials
Community Group
39 SSIMeetup.org

40. 40
The second generation DID spec
is currently being standardized by
the W3C Credentials Community
Group—membership is free
and open to all
SSIMeetup.org

41. 41
Work has begun to form the
W3C DID Working Group—this is
where the DID specification will
become an official
W3C open standard
SSIMeetup.org

42. 42
DID Specification Links
Implementers: please send feedback!
https://www.w3.org/community/credentials/
http://forum.sovrin.org/c/technical/did
SSIMeetup.org

43. 43
Thank You
SSIMeetup.org

44. Webinar: Decentralized Identifiers (DIDs)
The Fundamental Building Block of Self-Sovereign Identity
(SSI)
SSIMeetup.org07 May 2018
Drummond Reed
Chief Trust Officer Evernym and Sovrin Foundation Trustee
@drummondreed
https://creativecommons.org/licenses/by-sa/4.0/