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Senior Project - ISE


Selective Encryption of Images

Senior Project: 2003-2004
Shinya Daigaku, Geoffrey Griffith, Joe Jarchow, Joseph Kadhim and Andrew Pouzeshi

Compression of data has allowed for high-speed data transfer over the Internet. In addition to sending the smallest amount of information possible, users may desire to maintain a certain level of security. Due to the fact that common encryption methods generally manipulate an entire data set, most encryption algorithms tend to make the transfer of information more costly in terms of time and sometimes bandwidth. Thus, users pay a price for security proportional to their desired level of security. One possible solution is a system of encryption that works cooperatively with a standard compression scheme, encrypting only the smallest portion of the data that makes the entire data set unusable.

This project provides a package for selectively encrypting JPEG still image files. The package provides the tools necessary to encrypt the critical information within a JPEG file in cooperation with the existing compression scheme. The process encrypts less than 3% of the file no matter the size or resolution of the image. Once this small percentage of the file has been encrypted, the image is rendered useless without decryption. Selective Encryption extends to a level that would deter all but brute force attacks, allowing users to easily protect private JPEG images.

This project was sponsored by Associate Professor Tom Lookabaugh, who has also done research into selective encryption of MPEG-2 streams and speech coding. Professor Lookabaugh is the Faculty Director of the Interdisciplinary Telecommunications Program at the University of Colorado Boulder.

Encrypted Image Unusable
Encrypted Image Unusable
Decryption Yields Original Image
Decryption Yields Original Image
Encrypted Image Unreadable
Encrypted Image Unreadable
ISE Website
ISE Website
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Department of Computer Science
College of Engineering and Applied Science
University of Colorado Boulder
Boulder, CO 80309-0430 USA
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