1. Class 9 Physical Security and DRM CIS 755: Advanced Computer Security Spring 2014 Eugene Vasserman http://www.cis.ksu.edu/~eyv/CIS755_S14/

2. Administrative stuff Project proposal due today (2 pages) Quiz II and Exam I pushed back slightly – Quiz II next week

3. News! static OSStatus SSLVerifySignedServerKeyExchange(SSLContext *ctx, bool isRsa, SSLBuffer signedParams, uint8_t *signature, UInt16 signatureLen) { OSStatus err;... if ((err = SSLHashSHA1.update(&hashCtx, &serverRandom)) != 0) goto fail; if ((err = SSLHashSHA1.update(&hashCtx, &signedParams)) != 0) goto fail; if ((err = SSLHashSHA1.final(&hashCtx, &hashOut)) != 0) goto fail;... fail: SSLFreeBuffer(&signedHashes); SSLFreeBuffer(&hashCtx); return err; }

4. Trusted computing base (TCB) Software-level TCB Hardware-enforced software constraints Hardware-level TCB TPM:

5. Physical security Why use physical security? – Do Kerckhoffs’ principle or Shannon’s maxim apply? Tamper evidence Tamper resistance Properties? Differences? Assumptions? Trade-offs? Real-world examples

6. Blu-Ray DRM References “Broadcast encryption” An Overview of the Advanced Access Content System (AACS). Henry, Sui, and Zhong. Technical report, 2007. http://cacr.uwaterloo.ca/techreports/2007/cacr2007-25.pdf Revocation and Tracing Schemes for Stateless Receivers. Naor, Naor, and Lotspeich. Crypto, 2001. http://www.iacr.org/archive/crypto2001/21390040.pdf

7. Decryption Figure from the Overview tech report

8. Efficient keying and revocation Figures from the Overview tech report

9. Questions? Reading discussion