Loading in 5 sec....

The Effectiveness of Instruction Set RandomizationPowerPoint Presentation

The Effectiveness of Instruction Set Randomization

- 103 Views
- Uploaded on

Download Presentation
## PowerPoint Slideshow about ' The Effectiveness of Instruction Set Randomization' - bardia

**An Image/Link below is provided (as is) to download presentation**

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript

### The Effectiveness of Instruction Set Randomization

Where's the FEEB?: The Effectiveness of Instruction Set Randomization. Nora Sovarel, David Evans, Nate Paul.To appear at USENIX Security, August 2005

Nora Sovarel

http://www.cs.virginia.edu/nora

University of Virginia

Computer Science

2005 IEEE Symposium on Security and Privacy

Instruction Set Randomization Randomization.

Encryption Key

Decryption Key

Compile

Load

In memory

Execution

2-byte instruction Randomization.

Correct: infinite loop

Wrong:

Usually crashes

Sometimes false positive

False positives

Conditional jumps

Used to reduce the number of attempts (average 24 per byte)

Jump Attack: jmp -2eb

eb

fe

fe

cd

0xbfffe990

0xbfffe991

Requirements Randomization.

- Multiple guess attempts on same key
- Server forks process
- No rerandomization

- Remotely observable behavior
- Injection at known address
- Simple encryption scheme
- Byte-wise
- Learn key from one plain/cipher pair

Conclusion Randomization.

- It sometimes works
- Possible countermeasures
- Rerandomize periodically
- Stronger encryption

http://www.cs.virginia.edu/nora

Where's the FEEB?: The Effectiveness of Instruction Set Randomization. Nora Sovarel, David Evans, Nate Paul. To appear at USENIX Security 2005

Download Presentation

Connecting to Server..