Android 5.0 Lollipop encryption found to hamper storage performance by up to 80 percent

[Shawn Knight]

Android 5.0 Lollipop includes a bevy of new features and enhancements such as a remote kill switch and Trusted Places, among others. It’s also the first version of Android that enables Full Disk Encryption (FDE) by default on new devices. It’s a thoughtful gesture on Google’s part considering today’s privacy-conscious culture but as AnandTech recently discovered, it also severely hampers read / write performance.

The publication first noticed some anomalies when benchmark testing the storage system of the new Nexus 6 and decided to dig a bit deeper.

As you can see in the results above using AndEBench, FDE comes with a very significant performance penalty. With it enabled on the Nexus 6, random read performance dropped 62.9 percent while random write speeds were down 50.5 percent. The biggest hit, however, comes in the form of an 80.7 percent drop in sequential read speeds.

It’s worth pointing out that the Nexus 5 in their testing was running Android 4.4 then upgraded to Lollipop. When a user upgrades an older device to Lollipop, FDE isn’t automatically turned on – such is only the case on new devices that ship with Lollipop.

For those curious, FDE has been available since Android 3.0 Honeycomb but again, Lollipop is the first build to enable it by default on new devices.

The results almost seem unfathomable but it does make sense. With FDE enabled, all writes to disk are encrypted before being saved and conversely, all reads are decrypted before being sent to RAM.

What makes things worse is the fact that the key to decrypt is protected by the lockscreen password. That means that people who don’t use a passcode on the lockscreen (there are lots of people who don’t) are taking the performance hit without any gains from FDE.

With any luck, Google will find a workaround to speed up FDE reads and writes though given that it’s been around since Honeycomb (2011), it seems somewhat unlikely. At the very least, maybe they will reconsider whether it should be enabled by default.

If your Nexus 6 feels a bit laggy at times, this could be why. It may be worth turning FDE off for a bit to see if it helps speed things up. For now, however, users must decide if the added security is worth the performance trade-off. 

Permalink to story.

https://www.techspot.com/news/58932-android-50-lollipop-encryption-found-hamper-storage-performance.html

 

[Skidmarksdeluxe]

FDE may be appealing to some people but probably the majority, myself included couldn't be bothered with it, hopefully it'll become an option to use like in previous Android versions.

 

[hahahanoobs]

FDE may be appealing to some people but probably the majority, myself included couldn't be bothered with it, hopefully it'll become an option to use like in previous Android versions.

You have the option to turn it off. It's just on/enabled when you get the phone.

 

[insect]

And what's more is that this isn't really security. This prevents someone from reading the drive if they gain physical access to the device via USB, but it won't prevent software based security issues from reading your data (I.e., what the government, facebook, police, cellular carriers, etc. do.)

If someone steals your phone, sometimes the data is more valuable to them than the device, but I suspect most just re-sell the phone and move on.

 

[NimbusTLD]

Those results paint an incomplete picture without FDE results for Nexus 5 running Lollipop.

Also, you can't turn off FDE once it's turned on, so on a Nexus 6 or 9 where it's turned on by default, you're stuck with it. Anandtech received a special ROM from Motorola with it disabled.

 

[psycros]

Android gets uglier, less intuitive and more bloated with every release - the exact opposite of how it was supposed to go.

 

[Guest]

Hmm... in future chipmakers should include hardware acceleration for encrypting/decrypting engine into the SoC

 

[Jad Chaar]

Very interesting.

Android gets uglier, less intuitive and more bloated with every release - the exact opposite of how it was supposed to go.

And that is why I am an iOS guy.

 

[Tanstar]

Very interesting.

Android gets uglier, less intuitive and more bloated with every release - the exact opposite of how it was supposed to go.

And that is why I am an iOS guy.

Because it's better to start out with unintuitive and restrictive than to have ever known freedom and see it slip away?

 

[Skidmarksdeluxe]

You have the option to turn it off. It's just on/enabled when you get the phone.

Thanks.

 

[Guest]

I half suspect the guest is also an iOS user.

So a month or two ago, the lack of full encryption was deemed to be a horrible oversight.
A huge hole that needed fixing.
So now it's enabled by default on new Androids.
Encryption is NOT free (why would anyone think it costs nothing to do?).
And the performance hit is measured.
I wonder if "real world" applications show the huge differences that these targeted measurements show?
For example, if random reads are 1 percent of what an application does, and its random read times double, that means a 1 percent slowdown (in general) in that app's performance... I doubt most phone/mobile applications are things like high throughput databases where this would probably be more significant.
Just saying...

And yeah, it'd be nicer if it was faster.

 

[tipstir]

FDE is software base into the code. If it had it own hardware to speed it up then these number wouldn't be hurting the performance. This is first gen FDE. Give it time, they might able in other hardware improvement make it quicker.

 

[Guest]

I'm surprised Android 5.0 Lollipop don't utilize hardware encryption considering this feature has been around for a long time. As someone who owned a Western Digital My Passport Portable with hardware encryption support, I never want to go back to software-based encryption (used to use Truecrypt and Bitlocker).

If Samsung don't include hardware encryption support in its next line of Galaxy products then I would be very disappointed.

 

[psycros]

Very interesting.

Android gets uglier, less intuitive and more bloated with every release - the exact opposite of how it was supposed to go.

And that is why I am an iOS guy.

Very interesting.

Android gets uglier, less intuitive and more bloated with every release - the exact opposite of how it was supposed to go.

And that is why I am an iOS guy.

Yeah, Apple is pretty smart to copy all of Android's innovations while skipping most of their mistakes. Of course Apple screws up fairly regularly, too, but they've learned over the years to stop being arrogant about it and own up to their shortcomings. Google started out being very up-front about Android's direction but has slowly been turning into "old Apple". Its bizarre to watch.

 

[Guest]

You do not have the option of just turning it off.