This is an ambiguous question that requires a detailed answer.

“Zero knowledge” is an often misused term. It is not a term used in cryptography, and it appears to be a marketing buzzword rather than one originating from computer science. In fact, we believe other encryption vendors are using the term incorrectly and such use in marketing is an example of “snake oil” encryption.

According to the industry’s common definition of “zero knowledge” (which is technically incorrect) – the answer is yes, on the basis that neither Scram, nor your cloud storage provider, is able to read your data.

However, we can succinctly say that that no commercial solution in the marketplace is truly “zero knowledge”, but ScramFS is as “least knowledge” as is possible for a product of its kind, as explained below.

In our view, “Zero knowledge” literally must mean that your cloud storage provider knows absolutely nothing about you or your data. This must give you plausible deniability. However, in virtually every case, this is not the situation, because certain details are impossible to hide from cloud storage companies:

• Who you are (from your billing information)
• How often you access your data, and how much it changes
• Various attributes about your data - such as its total size, and how many files and directories that you have

The following table summarises the ScramFS solution in comparison to other typical solutions.

The who knows what summary table

Legend: Green = no data leakage / Red = data leakage

If data leakage is important to hide, the clear choice is the ScramFS solution and hosting your own private cloud.