Introducing EPID. A digital signature scheme.

1. Introduction to Intel EPID

2. 2
Intel Enhanced Privacy ID
EPID is a digital signature scheme with special properties:
• Single public key corresponds to multiple private keys
• Each unique private key can be used to generate a signature
• Signature can be verified using the group public key
• No one can tell which private key was used to generate a signature
RSA/DSA/
ECDSA
EPID
Pub-Key
Pvt-Key
Pvt-Key 1
Pub-Key
Pvt-Key 2 Pvt-Key 3

3. 3
Intel Enhanced Privacy ID
International Standard
• ISO/IEC 20008/20009 & TCG
• Privacy Preserving Anonymous Attestation
• RAND-Z licensing
Mature Technology
• Shipping since 2008
• Xeon, Core 2011
• Atom, 2014 → sub-Atom
• 2.4B Keys since 2008
Utilization of EPID
• Intel Insider (Digital Rights Management)
• Intel Trusted Execution Technology (Intel TXT)
• Intel Identity Protection Technology (Intel IPT)
• Intel Software Guard Extensions (Intel SGX)
Intel is Enabling the Industry on EPID

4. 4
Anonymity in practice
Anonymous GPS data
Likely there is a
traffic jam here:
49°26'33.3"N
11°05'14.0"E

5. 5
Linkability
Every 5 min
Thanks to full privacy EPID gives us we don’t even
know about messages coming from the same
source.
Sometimes that’s a problem...
EPID offers a parameter called basename to control
linkability.

6. 6
Revocation
Position:
38472384 N
23122333 E
EPID provides granular revocation mechanisms:
• Group Revocation (GroupRL)
• Private Key Based Revocation (PrivRL)
• Signature Based Revocation (SigRL)
• Verifier Blacklist Revocation
!?

7. 7
EPID Verification Service
• Publicly available web service
• Way to use EPID without diving into SDK, saves you from:
• Revocation list handling
• Key management
• Converts EPID signatures to standard ECDSA

8. 8
EPID Verification Service
Device
3rd party service
EPID Verification Service
ECDSA Proof
EPID Signature
ECDSA Proof

9. 9
Materials available for Hackathon
• EPID SDK:
• Sources
• Documentation
• Examples
• Precompiled libraries
• Simplified examples in C
• Locally hosted version of EPID Verification service
• EPID Cheatsheet