A group of researchers has demonstrated that smartphone batteries can offer a side-channel attack vector by revealing what users do with their devices through analysis of power consumption.

Both snitching and exfiltration were described in this paper (PDF), accepted for July’s Privacy Enhancing Technologies Symposium.

Nobody needs to panic yet, because the attack isn’t yet more than a decently tested theory,

https://sites.google.com/site/silbersteinmark/Home/popets18power.pdf?attredirects=1

BaseMark Announces The Power Assessment Tool (PAT)
by Andrei Frumusanu on March 2, 2016 10:01 AM EST
http://www.anandtech.com/show/10111/basemark-announces-the-power-assessement-tool

Basemark has traditionally been a software company. We’ve seen and used a lot of their benchmarking test suites including Basemark OS and Basemark X. Seeking to expand its portfolio by not only providing software benchmarks to quantify performance of devices, Basemark looks to provide hardware to enable users to measure power-consumption and power-efficiency of devices. Here is where the PAT (Power Assessment Tool) comes in. The PAT is a tool that doesn’t require destructive dismantlement of a device to be able to measure its power consumption. This is an area where I’m particularly familiar with as over the last year and more have been instrumenting a lot of smartphones via external power supplies and measurement equipment by physically opening them and replacing the lithium power cells.

Basemark relies on the fact that when smartphones are fully charged, they usually enter a power bypass-mode where the internal battery cell is no longer used, and power is instead drawn directly from the connected charger. To do this the PAT is connected to a conventional charger input. Currently this is a microUSB port but Basemark tells me future revisions might consider going USB C.

It’s still a bit early to talk about the capabilities of the beta software but Basemark shows promise and once all features are implemented the PAT should represent great value in terms of analysis for both professionals and enthusiastic hobbyists.

A software startup company based on a Purdue University innovation is helping to extend the life of smartphone batteries by helping application developers identify code that drains batteries quickly.

“There are two ways to address the problem of smartphone batteries draining quickly: the first is to invent a better battery. Battery capacity, which is the amount of energy that can be packed into a fixed form factor, is reaching its limit,” said Hu. “The other option is to make smartphone apps more energy efficient so they drain less of the battery. Mobile Enerlytics is developing software to make that happen.”

Purdue researchers have developed the technology that could help mobile app developers analyze millions of lines of code to identify ‘hotspots,’ or sections of code that drain most of the energy. The technology has been exclusively licensed to Mobile Enerlytics through the Purdue Office of Technology Commercialization.

“As mobile apps become more feature-rich, code easily reaches more than one million lines,” explained Hu. “My colleagues and I have found that a single line of code can create an energy hotspot. Sometimes simply changing the data structure or moving around a single line of code drastically reduces the resulting energy drain.”

“When a smartphone user starts Estar, it provides two options: to find energy-efficient apps in the app market or to stop power-hungry apps running on the phone,” said Hu. “When the first option is chosen, Estar provides a color-coded, five-star rating system that shows how fast a smartphone app will drain the phone battery, in the foreground and in the background, relative to other apps in the same category. Estar also makes a daily recommendation of apps based both on popularity and energy ratings.”

Mobile Enerlytics; http://www.mobileenerlytics.com/

he Samsung Galaxy Tab is smart enough to know which of its features use the most battery power. You can check it out for yourself:

At the Home screen, touch the Apps Menu icon button.

Choose Settings.

Choose About Tablet.

Choose Battery Use.

The number and variety of items listed on the Battery Use screen depend on what you’ve been doing between charges and how many apps you’re using.

The Systems Hacker’s Guide to the Galaxy
Energy Usage in a Modern Smartphone
http://www.nicta.com.au/pub?doc=7044

Instrumentation
Modern consumer devices such as smartphones have
a large number of power supplies for various compo-
nents, which, in theory, enable per-component analysis
of power consumptions. However, there are generally no
schematics available which would help identify the sup-
plies powering each component, nor are they equipped
with measurement capability.

Display power is a significant contributor in every sce-
nario where the display is active. Even at the 50% bright-
ness level it contributes 300–600 mW, highly dependent
on the image content—an inherent property of OLED
technology.

Galaxy Nexus Screen power consumption
http://www.youtube.com/watch?v=cqSQ5QE-4S0

Samsung Galaxy S3 Power Consumption Test.
http://www.youtube.com/watch?v=KD8HzaruWAU