Google has tossed a crumb of reassurance to people with cloudy security concerns by adding automatic server-side encryption to Google Cloud Storage.

The free security measure was announced by Google on Thursday and spun as a way to "make securing your data as painless as possible," according to a blog post by the company.

The change means data will be kept in RAM and encrypted via AES-128 upon upload into the service before being written to disk.

"There is no setup or configuration required, no need to modify the way you access the service and no visible performance impact," the company wrote. "The data is automatically and transparently decrypted when read by an authorized user."

The data and metadata of each Cloud Storage object will be encrypted with a unique AES-128 key, and the per-object key is encrypted with a further key associated with the owner. These keys are then encrypted by a rotated set of master keys.

"This feature adds to the default encryption functionality already provided by Persistent Disks and Scratch Disks that come with Google Compute Engine. Together, this means that all data written to unstructured storage on the Google Cloud Platform is now encrypted automatically, with no additional effort required by developers," Google wrote.

By implementing automatic encryption, Google has taken a lead on cloud rival Microsoft, which does not offer such a service. Information can be encrypted at rest and in transit in Azure, but this needs to be done proactively by the administrator.

As with most events in the cloud, Google is following Bezos & Co's gigantic Amazon Web Services division, which gave admins an option for automatic server-side encryption for S3 data back in 2011. The difference is that in Amazon admins must select encryption within the HTTP header of their object PUT request, whereas Google encrypts everything by default.

A report by the National Institute of Science and Technology (NIST) from 2012 estimated that AES-128 should be secure through to 2031, so the lack of 256 encryption shouldn't be too much of a cause for concern.

However, all bets are off if someone finally gets a quantum computer working at a large scale with a meaningful number of qubits, which should have enough oomph to tear through AES encrypted data in seconds.

Perhaps cognizant of this somewhat unlikely threat, Google got entangled with NASA in May for a joint $15m investigation into a Quantum-ish system from controversial company D-Wave Systems. If Google is publicly involved, then it's certain that intelligence agencies across the world have been fooling around with quantum-like gear for years, and for that reason if your organization has mission-critical data that absolutely cannot under any circumstance be seen by anyone else, then you should "search on" and look for an on-premises tech, preferably with an air gap between it and the public internet. ®