Lollipop’s Encryption Takes a Hefty Toll

There's a price to pay for the security afforded by encryption, and in the case of devices running Android Lollipop, the price apparently is a significant decline in performance. A general rule to keep in mind is, "the greater the security, the greater the overhead," said tech analyst Jim McGregor. However, "the performance of the silicon executing these solutions continues to increase as well."

The 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.”

Katherine Noyes has been reporting on business and technology for decades. You can find her on Twitter and Google+.

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