Cryptography For Privacy Preserving Data MiningCSE 4120 : Technical Writing & Seminar

Submitted by:MD. Mesbah Uddin Khan

Roll – 0707059 Dated, June 14, 2011

Things we need to know

PrivacyPrivacy PreservingPrivacy Preserving ComputationSecure ComputationsPrivacy Preserving Data MiningCryptography

Privacy (1/2)

Lets consider following facts:

• Separate medical institutions wish to conduct a joint research while preserving the privacy of their patients. • In this scenario it is required to protect privileged information, but it is also required to enable its use for research.

How can we solve this problem??

Privacy(2/2)Therefore we need a protocol

which…

is secure, i.e. original parties would require a third party who will do the computation and leave results to the original parties.

limits information leak in distributed computation.

Privacy Preserving

Ultra large database holds a lot of transactional records.

Privacy preserving protocols are designed in order to preserve privacy even in the presence of adversarial participants.

Adversarial participants attempt to gather information about the inputs of their peers.

Adversarial participantsTwo types of adversaries:

Semi-honest adversary◦ also known as a passive, or honest but

curious adversary

Malicious adversary◦ may arbitrarily deviate from the protocol

speciation

Privacy Preserving Computations (1/3)Classification

◦ Separate parties try to build decision trees without disclosing contents of their private database

◦ Algorithms: ID3, Gain Ratio, Gini Index etc

Data Clustering◦ Both parties want to jointly perform data

clustering◦ Performed based on data clustering

principles

Privacy Preserving Computations (2/3)Mining Association Rules

◦ Both parties jointly find the association rules from their databases without revealing the information from individual databases.

Fraud Detection◦ Two parties want to cooperate in

preventing fraudulent system, without sharing their data patterns.

◦ Private database contains sensitive data.

Privacy Preserving Computations (3/3)Profile Matching

◦ Mr. X has a database of hackers profile. ◦ Mr. Y has recently traced a behavior of a

person, whom he suspects a hacker. ◦ Now, if Mr. Y wants to check whether his

doubt is correct, he needs to check Mr. X’s database.

◦ Mr. X’s database needs to be protected because it contains hackers related sensitive information.

◦ Therefore, when Mr. Y enters the hackers behavior and searches Mr. X’s database, he cant view his whole database, but instead, only gets the comparison results of the matching behavior

Two distinct problems 1. Secure Computation:

◦ which functions can be safely computed.◦ safety means that privacy of individuals is

preserved.

2. Privacy Preserving Data Mining:◦ compute results while minimizing the

damage to privacy.◦ compute the results without pooling the

data, and in a way that reveals nothing but the final results of the data mining computation.

CryptographyCryptography is the practice and

study of hiding information.

Concluding Remarks

functions can be computed efficiently using specialized constructions

secure protocol for computing a certain function will always be more costly than a native protocol

Thank you all…