1. CryptDB: Protecting Confidentiality with Encrypted Query Processing
Raluca Ada Popa, Catherine M. S. Redfield, Nickolai Zeldovich, and Hari Balakrishnan
MIT CSAIL
Presenter Kecong Tang

2. DBA story Rules Some Jobs need to read the data
Should never read the data.
If you have to, FORGET them TOTALY after you’re done!
Some Jobs need to read the data
“hey we get data conflicted ”
“we need you to recover some data”
“we need a special data collection”

3. Problems
Online applications are vulnerable to theft of sensitive information.
Who?
Curious & Malicious DBA
Attackers gain Admin or DBA level access
What?
Confidentiality

4. Solutions:
CryptDB
Encrypted Query Processing

5. Introducing CryptDB Encrypted database Nothing is pain text
By different keys and encryptions
for different columns and users’ data

6. Three key ideas: SQL-aware encryption
Adjustable query-based encryption
Chain encryption keys to user passwords

7. SQL-aware encryption Different columns different Ops
different Encryptions
Ops: Sum, >,=,Order,Group,like…
Data still encrypted but Operational

8. Adjustable query-based encryption
Type Date usually for “order by”
What if I search “ ”?
Re-encryption to the required format.

9. Chain encryption keys to user passwords
Data is only availably when user login
Different users’ data different encryption keys
This can deal with SQL injection
Hacker will get encrypted data without keys

10. CryptDB’s architecture

11. Application server CryptDB proxy server DBMS server
Normal front web page
User login
Key setup to Database poxy
CryptDB proxy server
Active keys
Annotate schema
DBMS server
Normal DBMS with encrypted data
User defined functions to encrypt
Encrypted Key table

12. DBMS server Compromise full access DBA or attacker
Threat 1:
DBMS server Compromise
full access DBA or attacker
usually read data
Server cannot compute the (encrypted) results

13. All servers are compromised
Threat 2:
All servers are compromised
Different user different key
Inactive users’ key are not available
Only logged-in users’ key can be decrypted

14. Case Studies
phpBB is a widely used open source forum with a rich set of access control settings.
HotCRP is a popular conference review application
grad-apply is a graduate admissions system used by MIT EECS

15. Limitations Both computation and comparison on same column
WHERE salary > age*2+10.
Multi-principal can not encrypted to different format
order by date
where date=“ ”

16. Contribution Definitely improve Data Security
Prevent data leaking even the server totally compromise

17. Weakness Performance Data repair and Offical Investigate
Frequently Re-write
Time,update 1 column in an-over-100k-lines MYSQL table will take ???? minutes.
Harddrive life: frequently Harddrive writting
Data repair and Offical Investigate
It takes time even they can decrypt.

18. Improvement Should we open a Back Door?
“One button to decrypt all data”…

19. Thanks
Questions?