everything else (i.e., everything i didn't get around to...

Everything else (i.e., everything I didn't get around to teaching this semester, but wanted to)

“In five minutes, you learn what the average college graduate remembers five years after he or she is out of school.”

If you want to know more about something...

● Ask me● RTFM, RTFP, or RTFB● Google● Google Scholar (can see all the papers that cite

a paper)● All the places in the library where you can't sit

and study have periodicals, books, helpful people, etc.

Foundational results

● Access Control Matrix– Formally undecidable if a right leaks

● Take-grant model– Transitive closure

Policies

● Confidentiality– Bell-LaPadula: no reads up, no writes down

● Integrity– Biba's low-water-mark policy (if you read it, your integrity becomes the

minimum of what it is already and that of what you read)

– Biba's ring policy (who cares?)

– Biba's Model (Bell-LaPadula upside down)

– Lipner (who cares?) and Clark-Wilson (for business)

● Availability Hybrid Policies– Chinese Wall model (for conflicts of interest)

– CISSP (not even important enough to not have had its acronym stolen)

Lattice = partial ordering

Plagiarized from http://www.cs.cornell.edu/courses/cs5430/2012sp/mls.gif

Chinese Wall Model

Plagiarized from http://www.cs.cornell.edu/courses/cs5430/2012sp/chinWall.gif

Mechanisms

● Mandatory Access Control– System won't let users change, like SELinux

● Discretionary Access Control– Users can change, like UNIX file permissions

● Capabilities vs. access control lists● Weak Windows DACLs is a fascinating topic

– https://www.nccgroup.trust/uk/about-us/newsroom-and-events/blogs/2013/november/windows-dacls-why-there-is-still-room-for-interest/

– Gray Hat Hacking, 4th Edition by Harper et al.

– https://www.blackhat.com/presentations/bh-dc-07/Cerrudo/Paper/bh-dc-07-Cerrudo-WP.pdf

Information flow

● Multi-Level Security (Top Secret, Secret, Unclassified, etc. all on the same machine)– Kind of a stupid idea (think rainbow series)

● Noninterference (Goguen and Meseguer in 1982)– “A computer has the non-interference property if and

only if any sequence of low inputs will produce the same low outputs, regardless of what the high level inputs are.” (https://en.wikipedia.org/wiki/Non-interference_(security))

Information flow(continued)

● Denning's Lattice-based access control (1976)● Fenton's Data Mark Machine (1974)● Dynamic Information Flow Tracking (Suh et al.,

ASPLOS 2004, Crandall and Chong MICRO 2004)– A.k.a. Dynamic Taint Analysis (Newsome and Song 2005)

– Indirect flows are a problem

x = A[y] if (y==1)X = 1

Implicit flows

if (y == 1)x = 1

Even if y != 1, information flows from y to x!

Covert channels

● Confinement problem– Defined by Lampson in 1973

● Covert channel = path of communication that was not designed to be used for communication [Bishop, Chapter 17]

● Lipner (1975) distinguishes between timing channels and storage channels– Kemmerer's (1983) Shared Resource Matrix Methodology can be

used for storage channels, basically a transitive closure

– Wray (1992) considered timing channels, can compare all pairs of “clocks”

Side channels

● Covert channels assume collusion● Side channels can be used to infer information

– Key stroke timings leaking through entropy pool (Silence on the Wire by Zalewski)

– Keyboard Acoustic Emanations https://www.davidsalomon.name/CompSec/auxiliary/KybdEmanation.pdf

– Cache missing for fun and profit http://www.daemonology.net/papers/cachemissing.pdf

– Lots of other examples...

● “Information wants to be free”

Thomas Jefferson said...

“That ideas should freely spread from one to another over the globe, for the moral and mutual

instruction of man, and improvement of his condition, seems to have been peculiarly and

benevolently designed by nature, when she made them, like fire, expansible over all space, without lessening their density in any point, and like the

air in which we breathe, move, and have our physical being, incapable of confinement or

exclusive appropriation.”

Digital forensics

● According to Wikipedia, you could be looking for: attribution, alibis and statements, intent, evaluation of source, document authentication

● File carving– Electron microscopes

● Memory forensics● Network forensics (PCAPs, NetFlow records, NIDS logs)● Database forensics● Steganography● Digital forensic processes● Benford's law

Malware

● Cryptovirology by Young and Yung● The Art of Computer Virus Research and Defense by Szor

– Common theme since the turn of the millennium: stay in memory and don't go out to disk

● Elk Cloner in 1981 (Skrenta)● “Virus” coined by Cohen in 1983 (“Information only has meaning in that it is

subject to interpretation”)– https://web.eecs.umich.edu/~aprakash/eecs588/handouts/cohen-viruses.html

● “Worm” came from John Brunner's The Shockwave Rider in 1975– Creeper in 1971 for TENEX systems

– ANIMAL in 1975

– Morris Worm in 1988

– Code Red in 2001

Anomaly detection

● A Sense of Self for Unix Processes (Forrest et al. in 1996

Privacy and anonymity

● Onion routing– Tor

● User tracking (e.g., cookies)– Panopticlick

– Snowden revelations revealed that the NSA was exploiting commerce-based user tracking

● SSL/TLS sucks

Resources

● Cryptography and Data Security by Dorothy Elizabeth Denning

● Computer Security: Art and Science by Matt Bishop

● https://www.youtube.com/watch?v=kO8x8eoU3L4

● Practical Malware Analysis by Honig and Sikorski

Conferences

● IEEE Symposium on Security and Privacy (Oakland)● USENIX Security Symposium

– Also check out the workshops like FOCI and WOOT

● ACM Conference on Computer and Communications Security (CCS)

● Network and Distributed System Security Symposium (NDSS)● Privacy-Enhancing Technologies Symposium (PETS)

– Also PoPETS

● Also RAID for intrusion detection, DFRWS for forensics, CSF for policy and theory, Eurocrypt and Crypto, Blackhat, DEFCON, phrack, 2600 magazine, WPES and WEIS