|
|
SECURITY LAB SEMINAR
May 5, 1999
1-2pm
1131 ENG II
User Profiling in Relational Database Systems
Presented by Christina Chung
Slide Presentation
Abbreviations: CC: Christina Chung, KL: Karl Levitt, MB: Matt Bishop,
MG: Michael Gertz, RP: Raju Pandey, TA: Tuomas Aura, CW: Chris Wee
Questions
- KL: Help with integrity?
- CC: Monitoring of data
- CW: Query in data is small
- CC: Log actual data that is changed; log query itself ² see whatžs
changed
- MG: What is your definition of "complete" for profiles?
- CC: With respect to training set ² compare test data from profile.
- MB: Static profiles or profiles over time?
- CC: It depends on the type of data you're interested in. I donžt
deal with temporal patterns yet.
- MB: Profile wonžt change over lifetime?
- CC: Yes, this is a feature to add on later.
- TA: Example of use for this database system?
- CC: Profiling for fixed known behavior.
- CC: With applications, certain set of fixed queries. TA: Catch
person who uses new things. CC: User behavior is not stable. TA: Trying
to catch changes in behavior CC: Intrusion and insider abuse. Match
it against policy ² compare profiles with policy. TA: It will detect
any change in behavior. CC: Typical or expected behavior.
- MB: Profiler is a statistical aggregation of patterns of behavior.
Policy is an aggregation of actions.
- MG: You have actions in a profile.
- RP: Way to arbitrarily add C programs. OS and programming languages
are action based.
- CW; Types of security ² what is the class of threats youžre interested
in?
- CC: Invasion of sensitive information. Insider threat
- CC: Data model and information of data is specified. Type of threat
- information theft more interesting than DoS.
- What if the access affinity between A1 and A7 is high?
- CC: If they are referenced very often together, something is wrong
with diagram. MG: Or user? User found some correlation. CC: Keys missing
in ER diagram. MG Compare attribute values for A1 and A7.
- RP How are clusters different from working scopes? User-defined clusters.
- CC: Cluster ² only consider the object, attribute and select queries.
- KL: Donžt capture semantics of database?
- CC: Doesnžt capture that.
- RP: What do I do with profilers?
- CC: Detect misuse by comparing profiles with policy. Specify in
policy ² discover profiles of user.
- RP: Example ² make my profile as big as possible. Make my cluster
to cover the entire schema.
- CC: Domain knowledge ² security officer will set threshold amount
for distance measure. Assumption that the training data is bad. Known
patterns in training data ² meaningful threshold to set.
- CW: Is it reasonable that one can obtain training data?
- CC: Trying to generate my own.
- TA: Working in office, accessing same databases.
- MG: Interactive process. Not necessarily clean ² confidence level
generated. Feedback corresponds to reality. Iterative process.
- MB: OS systems are just databases; parallel between anomaly detection.
Take this and apply it to anomaly detection? Fundamentally different
here?
- CC: Capability ² SQL query to process large amounts of data. I
do clustering in SQL. Data structure is different. OS has no data
structure.
- RP: How effective is the data in small changes?
- CC: Crucial step - how we group audit sessions. Profiles for different
window frames.
- MG: You can specify some kind of rules; specify how rules must
behave; meta rules that you apply.
- RP: It seems to me that it is based on distance analysis. Distance
is very inaccurate. Can be defeated by delta distances. CC: Deviation
of behavior. Profile just discovers profile.
- RP: What will happen to this data? CC: Temporal patterns.
- TA: What kind o f behavior do you detect with that? Do one query
thatžs not allowed. Need change in behavior.
- CC: Low threshold- high false alarm. TA: Avoid being caught by
doing secret queries. CC: User tradeoff.
- TA: Queries all the time; snoop peopležs salaries. MG: Layout of
database ² query out of working scope?
- MG: Really far away from working scope is more suspicious. Donžt
have a system where you have privileges established.
- MB: Can you use this on statistical bases? Can you bar people from
seeing certain entries?
- MG: Possible.
- CC: Not talking about statistical databases ² just relational databases.
- TA: Neural networks
- CC: Difficult to understand. Clusters more intuitive.
- CW: Looking at databases, written off application auditing project.
- TA: Once set up policies and profiles ² not how people actually
work.
|