1. 2
Cloud Computing
Transforms the way IT is consumed and managed, bringing costs down
Service delivery (NIST 2011)
SaaS (Software)
PaaS (Platform)
IaaS (Infrastructure)
“If you have an application exposed to the Internet that will allow people to make money, it will be probed.”
- Dave Cullinane, Former CISO, eBay.

2. Security issues in clouds3
Security issues in clouds
Cloud Security Alliance
Data breach
Data loss
Malicious insiders
Shared technology vulnerabilities …
NIST
Audit and compliance (e.g. cross border)
Response to a breach

3. Data breach Some example attacks from academic Crypto literature4
Data breach
Some example attacks from academic Crypto literature
Some example attacks from academic Crypto literature

4. 5
Overall Picture

5. Cryptographic solutions: a glimpse6
Cryptographic solutions: a glimpse
Password security
Attribute based encryption
Fully homomorphic encryption
Searchable encryption
Format preserving encryption
Functional encryption …

6. 7
Password Security
(Age-old) Password security problem

7. Searchable encryption8
Searchable encryption
Secure search over encrypted data
Adaptive/Non-adaptive multi/single user, variable/constant # rounds …

8. Fully homomorphic encryption9
Fully homomorphic encryption
Enc(m1) * Enc(m2) = Enc(m1*m2)
Enc(m1) + Enc(m2) = Enc(m1+m2)
Extremely powerful primitive
Allows working on encrypted data without revealing the plain data

9. Format Preserving Encryption
1010
Format Preserving Encryption
Picture source: Voltage.com

10. Attribute based encryption
1111
Attribute based encryption
Encryption based on policies
Decryption can be done when some specific attributes are satisfied
sales OR
IT dept.
manager
marketing
hire date < 2002
2 of 3
AND
exec. level >= 5
Figure source: Brent Waters’ slides

11. Thank you somitra@iiitd.ac.in
1212
Thank you
For more information, please contact Dr. Somitra Sanadhya
Cryptology Research Group, IIIT Delhi