Overview of Zero-Knowledge Systems Inc Overview of Zero-Knowledge Systems Inc. and the Private Credentials Technology December 5th 2000 Eric Bergeron General Manager – Wireless Solutions All information contained within is CONFIDENTIAL AND PROPRIETARY INFORMATION © Zero Knowledge Systems Inc, November 18, Montreal, Canada. All rights reserved.

Privacy – What is it? Information self-determination The claim of individuals, groups or institutions to determine for themselves when, how, and to what extent information about them is communicated to others Personally Identifiable Information (PII) is any information which can be used to identify a specific individual Not just name, address, SSN/SIN Data elements such as date of birth + zip code, or transactional history can narrow the focus down to a small enough group of people to be considered PII In an increasingly networked world, the privacy issue is becoming more and more important Ease and speed of information capture, storage and dissemination Online/offline profile matching Cross-site tracking using cookies, web bugs, etc. Internet connected appliances Wireless location-based tracking

OECD 8 Principles of Fair Information Practice Defining Privacy vs. Security OECD 8 Principles of Fair Information Practice Collection Limitation Data Quality Purpose Specification Use Limitation Openness Individual Participation Accountability 5. Security safeguards Security is a sub-set of privacy. You can address all of your security concerns without addressing privacy.

Zero-Knowledge Private Credentials

Digital Certificates Sequences of zeros and ones (of a mathematical structure) Verifiable with 100 % accuracy by computers Transferable electronically (no human intervention, fast) Unforgeable (crypto protection) Can specify any kind of data

Drawbacks to organizations Transaction delays Lost business (faulty/ irrelevant data, online connection fails) Central database verification Hard to protect databases against hackers and insiders Privacy standards bring compliance costs Manage CRLs / online validation

Privacy Concerns Traceability (CA, verifiers, wiretappers, intel. agencies) Discrimination (consults any database) No control over secondary use Revocation (CRL, online whitelists)

Private Credentials Similar to coins and public transport tickets (not identifiable) Encode attributes in the private key Selectively disclose the attributes Practical Security benefits

Selective Disclosure Show part of attribute data without revealing more (think: marker) More powerful than paper-based certificates (Boolean properties, n out of m, intervals) Works across different Private Credentials

Fraud Protections Reduce identity fraud Eliminate central database risks Discourage lending (encode secret of user) Discourage discarding (tie unfavorable attributes in) Limited-show property (identity computable if shown too often)

Private Payment (E-Cash) Special case of private credential System prototype is working today An attribute contains information about a currency (issuer, denomination, etc.). Always Revealed in the showing protocol An attribute contains personal information for “off-line fraud tracing”. Never revealed in the showing protocol The payment is the transcript of a showing protocol

Sample Applications Prepaid for Mobile Phones Private Payment (e-cash) for ME-Commerce ID cards (with privacy) Road-toll and public transport pricing/ticketing Digital copyright protection (certificates permit use of works) Access control (VPNs, subscription services, Web sites, databases) Medical prescriptions / medical files Electronic voting Online auctions Financial securities trading Electronic gambling Loyalty schemes

Smartcard Implementation Strong protection against loss, theft, extortion, lending,copying, discarding, etc. Uses mathematical primitives which are present in crypto enabled smartcards. Can be used in conjunction with desktop computer, PDA, etc. in which case we can use standard 8-bit smartcards.