IRMA: I Reveal My Attributes

Transcription

1 IRMA: I Reveal My Attributes Roland van Rijswijk - Deij roland.vanrijswijk@surfnet.nl rijswijk@cs.ru.nl

2 Project partners 2

3 What is an attribute? An attribute is a property of a person: Full name Date of birth Social Security Number address Over 18 Younger than 65 Student Enrolled curriculum Home institution (university, college,...)... 3

4 We are already using attributes The identity federations used in academia rely heavily on the use CONEXT of attributes (e.g. SURFconext or InCommon) Most identity federations rely on the SAML2 protocol Authentication in SAML2 relies on release of attributes about a user by an IdP to an SP 4

5 Attribute-based Authentication Issuer In a federation: Identity Provider (IdP) ➊ ➋ In a federation: Service Provider (SP) User ➍ ➌ Relying Party 5

6 Privacy and Attributes There are two kinds of attributes: Non-identifying attributes (e.g. over 18 ) Identifying attributes (e.g. name, SSN, address,...) Users traditionally have little control over their privacy In some federations this situation is improving with the introduction of user consent 6

7 Technology under the hood of IRMA IRMA is based on the Idemix technology, developed by J. Camenisch and A. Lysyanskaya at IBM Research in Zürich Idemix is an extremely privacy-friendly attributebased authentication technology Idemix gives the user full control over her attributes 7

8 Key properties of IRMA Key properties of the technology behind IRMA: Non-transferability Attributes are protected against copying Issuer unlinkability Issuers of attributes cannot trace use of these attributes Multi-show unlinkability Colluding service providers cannot retrace use of attributes to an identifiable user These properties rely on novel cryptographic techniques like zero-knowledge proofs and blind signatures 8

9 Zero-knowledge Proofs A Peggy Victor B 9

10 Zero-knowledge Proofs Victor A B 10

11 Zero-knowledge Proofs Victor A B 10

12 Zero-knowledge Proofs Victor A B 10

13 Zero-knowledge Proofs A B 11

14 Zero-knowledge Proofs A B B 11

15 Zero-knowledge Proofs A B 12

16 Zero-knowledge Proofs A OK! B 12

17 Zero-knowledge Proofs A Peggy Victor B 13

18 Zero-knowledge Proofs Victor A B 14

19 Zero-knowledge Proofs Victor A B 14

20 Zero-knowledge Proofs A B 15

21 Zero-knowledge Proofs A A B 15

22 Zero-knowledge Proofs A B 16

23 Zero-knowledge Proofs After 20 iterations the probability that Peggy correctly guesses the exit path chosen by Victor is less than 1 in 1.05 million A OK! B 16

24 Structure of Credentials secret key attributes issuer's digital signature Credentials consist of: A secret key A number of attributes that can be revealed independently (called selective disclosure) A digital signature by the credential issuer 17

25 Examples of Credentials Minimum age 12 years 16 years 18 years 21 years Seniority 50 years 60 years 65 years 75 years Anonymous (Partially) identifying Address Country City Street + number ZIP ID SSN Date-of-birth Place-of-birth Sex 18

26 IRMA smart card Front Back MULTOS smart card with Idemix implementation Only identifying information is a photo 19

27 Demonstration DEMONSTRATION 20

28 Point-of-Sales terminal demo 21

29 Pilot Project We have recently started with a pilot project Participants are students and staff of the Kerckhoffs institute about 100 students some 20 people in the staff Goal of this project is to trial the IRMA card in practice, with real users 22

30 Use cases Online: Reduced price for software purchased online ( SURFspot ) Access to course-related materials (e.g. grading of teachers)... (suggestions welcome) Offline: Reduced price coffee at several teaching locations Free printing for students at one teaching location... (suggestions welcome) 23

31 External Interest Over the course of the project we have organised (and will organise) public meetings There is a broad interest from business and government E.g. Ministry of Internal Affairs, Tax Office, DMV Ministry of IA has funded additional work 24

32 Future Work Revocation of credentials is an open problem and subject to extensive research Interaction with the user is another open issue Which attributes are to be revealed is now listed on a webpage owned by the relying party We want to perform a user study after the pilot 25

33 Conclusions IRMA shows that privacy and strong authentication are not mutually exclusive Authentication does not require identification Attributes have the future, also outside of identity federations The technology is promising but more research is required to lift it to production ready status 26

34 Questions? Remarks?