1. Public Key Infrastructure (PKI)

2. What is PKI?
“A public key infrastructure (PKI) is a set of roles, policies, and procedures needed to create, manage, distribute, use, store, and revoke digital certificates and manage public-key encryption.
The purpose of a PKI is to facilitate the secure electronic transfer of information for a range of network activities such as e-commerce, internet banking and confidential .
It is required for activities where simple passwords are an inadequate authentication method and more rigorous proof is required to confirm the identity of the parties involved in the communication and to validate the information being transferred”
Wikipedia

3. SWIM Objectives The Yellow Profile (YP) targets:
Support for a wide variety of interactions in a flexible manner and that is affordable for the service consumer
The interaction must be able to run over Public Internet and must be sufficiently secured
Use of technologies based on standard Web Services
The technology must be supported out-of-the-box
Keeping as many options open as possible
PKI based security solutions supports the above by:
Support for message signing to satisfy integrity, identification, authenticity and more
PKI is not restricted to yellow profile.

4. Business drivers Provider and consumer interaction build on trust
All involved parties can be trusted (authorized entities only)
Exchange mechanism can be trusted (secured, reliable, on-time)
Information can be trusted (non-repudiation, accountability)
No abuse of information (adequate access control)

5. Comprehensive PKI Certification Authority Certificate Repository
Revocation
Key
Backup
Recovery
Automatic Key
Update
Key History Management
Cross
Client
Software
Authentication
Integrity
Confidentiality
Secure Time
Stamping
Notarization
Non-repudiation Support
Secure Data
Archive
Privilege/Policy
Creation
Privilege/Policy Verification

6. Aeronautical PKI Architecture
USA
Root
CA / RA
EUR USA
Bridge
Certificates
EURRoot
FAA
Root
Policy 1
Policy 2
Policy 3
CA / RA
EDxx Airports
Example based on discussions with FAA. ICAO’s role have to be further elaborated and coordinated with ICAO.

7. One bridge-two certificates
A bridge between to separate PKI’s consists of two certificates between the PKI’s root certificates
USA shows that it trusts EUR by signing EUR’s public key with USA’s private key
Thereby issuing a new certificate “USA trusts EUR”
EUR shows that it trusts USA by signing USA’s public key with EUR’s private key
Thereby issuing a new certificate “EUR trusts USA”

8. The Bridge
Only two certificates to administer to trust across the Atlantic ocean
Can easily and automatically be revoked from Europe towards USA and vice versa
CPH have validated this scenario with standard tools available today on the internet

9. Different types of certificates
All are issued under the X.509 standard
The different types of certificates are issued according to different policies and by different intermediate certificate
The format and content of the fields can be different
Ideas for types and policies of certificates
Different certificates (policies) for different purposes (criticality)
Airlines, Airports, ANSP, Suppliers / Ground handler
Personnel in the above (ATSEP, Cabin Crew, Pilots)

10. Policies and Governance
Who generates the private key for each certificate?
How does the public key (certificate) get signed?
How to establish initial trust between CA and certificate users (ANSP, Airport, AO)?
Who can obtain a certificate?
What can they be used for?
What is the format and other content?
CA / RA
EURRoot
Policy 1
Policy 2
Policy 3

11. Policy 1 – high criticality example
Who generates the private key for each certificate?
By national security service and kept in the “vault” of the national trust store
How does the public key (certificate) get signed?
Transported by courier and with senior officials from CA present
How to establish initial trust between CA and certificate users (ANSP, Airport, AO)?
The same way diplomats become accredited
Who can obtain a certificate?
Only ANSP’s or Military
What can they be used for?
Only to be used to secure very critical infrastructure
What is the format and other content?
To be defined, depends on business context

12. Policy 2 – low criticality example
Who generates the private key for each certificate?
The CA generates and keeps the private key
How does the public key (certificate) get signed?
Automatically by the CA’s servers
How to establish initial trust between CA and certificate users (ANSP, Airport, AO)?
By an from the relevant organization (AO, ANSP, Airport)
Who can obtain a certificate?
Any organization in the industry
What can they be used for?
Any information that needs to be kept confidential or signed
What is the format and other content?
To be defined, depends on business context

13. Additional