1. Copyright © 1995-2006 Clifford Neuman - UNIVERSITY OF SOUTHERN CALIFORNIA - INFORMATION SCIENCES INSTITUTE USC CSci599 Trusted Computing Lecture notes Spring 2007 Dr. Clifford Neuman University of Southern California Information Sciences Institute

2. Copyright © 1995-2006 Clifford Neuman - UNIVERSITY OF SOUTHERN CALIFORNIA - INFORMATION SCIENCES INSTITUTE Administration Class home page http://ccss.usc.edu/599tc –Preliminary Syllabus –Assigned Readings –Lecture notes –Assignments See me for D Clearance

3. Copyright © 1995-2006 Clifford Neuman - UNIVERSITY OF SOUTHERN CALIFORNIA - INFORMATION SCIENCES INSTITUTE Administration Class e-mail: csci599s07@clifford.neuman.name Instructor –Dr. Clifford Neuman –Office hours Friday 10:45-11:45 SAL 212

4. Copyright © 1995-2006 Clifford Neuman - UNIVERSITY OF SOUTHERN CALIFORNIA - INFORMATION SCIENCES INSTITUTE USC CSci599 Trusted Computing Lecture Two – Trusted Hardware January 19, 2007 - PRELIMINARY Dr. Clifford Neuman University of Southern California Information Sciences Institute

5. Copyright © 1995-2006 Clifford Neuman - UNIVERSITY OF SOUTHERN CALIFORNIA - INFORMATION SCIENCES INSTITUTE NOTE These are place holders for the topics we will discuss today. There will be more slides by lecture.

6. Copyright © 1995-2006 Clifford Neuman - UNIVERSITY OF SOUTHERN CALIFORNIA - INFORMATION SCIENCES INSTITUTE The Hardware Basis Trusted computing is proof by induction –Each attestation stage says something about the next level –Just like PKI Certification hierarchy One needs a basis step –On which one relies –Hardware is that step ▪ (well, second step anyway)

7. Copyright © 1995-2006 Clifford Neuman - UNIVERSITY OF SOUTHERN CALIFORNIA - INFORMATION SCIENCES INSTITUTE Hardware Topics Trusted Platform Module Discussion of Secure Storage Boot process

8. Copyright © 1995-2006 Clifford Neuman - UNIVERSITY OF SOUTHERN CALIFORNIA - INFORMATION SCIENCES INSTITUTE Trusted Platform Module Basically a Key Storage and Generation Device Capabilities: –Generation of new keys –Storage and management of keys ▪Uses keys without releasing

9. Copyright © 1995-2006 Clifford Neuman - UNIVERSITY OF SOUTHERN CALIFORNIA - INFORMATION SCIENCES INSTITUTE Endorsement Key Every TPM has unique Endorsement key –Semi-root of trust for system –Generated and installed during manufacture ▪Issues –Real root is CA that signs public key associated with Endorsement key

10. Copyright © 1995-2006 Clifford Neuman - UNIVERSITY OF SOUTHERN CALIFORNIA - INFORMATION SCIENCES INSTITUTE Identity Key Key associated with certificate from a CA attesting to identity of the TPM and version / security attributes. (I’m not sure of the relationship with the EK)

11. Copyright © 1995-2006 Clifford Neuman - UNIVERSITY OF SOUTHERN CALIFORNIA - INFORMATION SCIENCES INSTITUTE Storage Root Key Root of Key Hierarchy for managing keys related to TPM (except EK) –Root key never leaves TPM –Can be changed to reinitialize ownership.

12. Copyright © 1995-2006 Clifford Neuman - UNIVERSITY OF SOUTHERN CALIFORNIA - INFORMATION SCIENCES INSTITUTE Storage Keys Can protect data Can protect other keys Some storage keys may be migrated.

13. Copyright © 1995-2006 Clifford Neuman - UNIVERSITY OF SOUTHERN CALIFORNIA - INFORMATION SCIENCES INSTITUTE Binding Key Private key to decrypt data perhaps encrypted by others using a public key

14. Copyright © 1995-2006 Clifford Neuman - UNIVERSITY OF SOUTHERN CALIFORNIA - INFORMATION SCIENCES INSTITUTE Using Encryption LoadKey –Generated or imported Sign –Signs Data Presented to TPM Unbind –Decrypt data from elsewhere in a public key

15. Copyright © 1995-2006 Clifford Neuman - UNIVERSITY OF SOUTHERN CALIFORNIA - INFORMATION SCIENCES INSTITUTE Using Encryption Seal/Unseal –Encrypt and subsequent decrypt –This TPM Only –PCRs must be correct Platform Configuration Register (PCR) –20 by storage inside TPM is digest of accumulated data. –Contains information about the programs and other state of the processor.

16. Copyright © 1995-2006 Clifford Neuman - UNIVERSITY OF SOUTHERN CALIFORNIA - INFORMATION SCIENCES INSTITUTE Using Encryption Extend –Add data to a PCR –20 byte hash hashed into current PCR –As each module loaded its hash extends the PCR Quote –Sign current value of PCR

17. Copyright © 1995-2006 Clifford Neuman - UNIVERSITY OF SOUTHERN CALIFORNIA - INFORMATION SCIENCES INSTITUTE Using Encryption CreateWrapKey –Creates and encrypts for transfer a new RSA key MakeIdentity –Creates an Attestation Identity key for a user TakeOwnership –Reinitialize TPM, and erases old keys

18. Copyright © 1995-2006 Clifford Neuman - UNIVERSITY OF SOUTHERN CALIFORNIA - INFORMATION SCIENCES INSTITUTE Using Encryption Other Functions –OIAP/OSAP –GetCapability –GetRandom

19. Copyright © 1995-2006 Clifford Neuman - UNIVERSITY OF SOUTHERN CALIFORNIA - INFORMATION SCIENCES INSTITUTE How to Use it For Atestation As modules loaded, their hashes extend the PCR. When attestation needed, remote entity can ask the TPM to sign PCR.

20. Copyright © 1995-2006 Clifford Neuman - UNIVERSITY OF SOUTHERN CALIFORNIA - INFORMATION SCIENCES INSTITUTE Peripheral Authenication TPM’s can be embedded in peripherals too, so a system knows it is dealing with an authentic biometric scanner or other kinds of devices.

21. Copyright © 1995-2006 Clifford Neuman - UNIVERSITY OF SOUTHERN CALIFORNIA - INFORMATION SCIENCES INSTITUTE Exercise - Secure Storage Full Disk Encryption –Key in register in disk –Or key in TPM and data encrypted/decrypted by TPM Seagate Drive uses register in Disk –Key must be loaded –User prompt at BIOS –Or managed by TPM ▪But OS image maybe on disk, how to get

22. Copyright © 1995-2006 Clifford Neuman - UNIVERSITY OF SOUTHERN CALIFORNIA - INFORMATION SCIENCES INSTITUTE The Boot Process –Work and example using the functions described already.