PORTLAND, Ore. -- Selective encryption can protect the most important content in wireless streaming video without running down batteries on mobile devices, according to a university researcher.
Today users must choose between using unsecured wireless transmissions and running down their battery with encryption algorithms just to prevent eavesdropping on video streams. The selective encryption approach could cut battery usage, said Wei Wang, an engineering professor at South Dakota State University in Brookings who headed the five-university research team that investigated the technique.
“We want to achieve good quality and strong security with limited battery and limited computing power,” Wang said.
By dissecting the content of streaming video files, the researchers identified those elements that require detailed rendering and separated them from those requiring less resolution without affecting the overall video. The encryption routines then dedicate more resources to the encryption of important elements, while using faster encryption routines for the elements that can get by with less fidelity. The result is less energy used to encode and decode streaming video.
Wang's team has demonstrated that single image files can be dissected to discern those areas that need detailed rendering and those that don't require strong encryption. For instance, a scanned bank check requires high-fidelity for rendering its numbers and amounts, but weak encryption is sufficient for solid color.
The researcher hope to convince industry to adopt their technique fo use in adjusting encryption accuracy on the fly to reduce power consumption in mobile devices.
Sounds like a good approach, but I wonder how much is saved (on average - I am sure it is media/image dependent) versus what additional power is used in the initial analysis? Looks like it works but getting major acceptance could prove a challenge.
Selective encryption reduces security by making it easier to find the data worth decoding. For example a check image would highlight a target of interest - even if part were encrypted. A clear text online order would provide valuable contextual information even if the credit card information were encrypted. With overall encryption, a lot of effort can be devoted to decoding what proves to be useless information.