Lollipop's Encryption Takes a Hefty Toll

T he new full-disk encryption feature that's enabled by
default in Android 5.0 Lollipop comes at a hefty price in
terms of performance, according to a recent benchmark
report.
In fact, when full-disk encryption is enabled, random read
performance drops by 62.9 percent, while random write
performance falls by 50.5 percent, AnandTech reported late
last week. Sequential read performance, meanwhile, drops
by a whopping 80.7 percent.
The bottom line is "serious negative implications for device
performance in any situation where applications are reading
or writing to disk," the report concludes.
How to Disable FDE
With full-disk encryption, all information is encrypted
before it's written to disk. Accessing the information
requires decryption, which is protected by the device's
lockscreen passcode.
A Nexus 6 was the device evaluated in this latest
benchmark report. Normally it's not available without full-
disk encryption, but Motorola reportedly provided a build
with the feature disabled for the purpose of comparison
testing.
Instructions for disabling Lollipop's encryption feature on the
Nexus 6 are now available on the XDA developers'
forum.
'There's a Cost'
"There's a cost that comes with encrypting and decrypting
stuff," said Ronald Gruia, director of emerging telecoms at
Frost & Sullivan .
In the wake of the Edward Snowden leaks and "rampant
security breaches" throughout the year, Apple took the lead
and closed the "final back door" in its platform with iOS 8,
he told TechNewsWorld.
Then, "Google had to match that," Gruia said. "It had
offered full-disk encryption since version 3.0 'Honeycomb,'
but only now is it on by default."
'Some Will Pay the Price'
In general, the idea is to improve privacy by making
snooping more and more difficult -- including even for law
enforcement, Gruia noted.
Will users be willing to accept a performance hit for that
increased privacy? Some will, but some won't, he
observed.
"I'm not so concerned with privacy, so I'd be more mindful
of the performance hits," Gruia said, "but some privacy
advocates who are gung-ho will be willing to pay the
price."
One twist particularly worth noting is that the benefits of
full-disk encryption in this case depend on users'
establishment of a passcode, he added, yet users who don't
set one up will still suffer the technology's performance hit.
"You must have the lockscreen enabled," he said. "Without
it, you get the worst of both worlds."
A Simple Fix
The lag in performance "will be annoying for users for a
while, but it won't be the end of the world because it will
be fixed," tech industry analyst Jeff Kagan told
TechNewsWorld.
"As each new generation of technology is rolled out, there
are always issues that need to be resolved -- that is simply
the state of today's marketplace," he explained.
"I am assuming that Google will be able to fix this quickly,"
added Kagan. In the meantime, "users will be knocking
their heads against the wall, frustrated with poor
performance."
Security vs. Overhead
Security should be a primary concern for the industry, and
"we have to realize that it will cause a hit in performance
and likely battery life in the initial implementations," said
Jim McGregor, founder and principal analyst with Tirias
Research .
A general rule to keep in mind is, "the greater the security,
the greater the overhead," he told TechNewsWorld.
However, "you have to remember that the performance of
the silicon executing these solutions continues to increase as
well," McGregor pointed out.
"So, the performance hit by the next generation of silicon
and devices is likely to be less than the current generation
-- especially when the silicon vendors have the opportunity
to optimize around these types of functions," he predicted.
"In the end, the benefits will outweigh the limitations."