Swiss Army knife firm Victorinox has pulled the plug on the security software used by its combined knife-and-USB stick products and has advised customers to back up their data by 15 September.

In a notice posted on Facebook and noticed by Engadget, the company said it planned to stop offering the security software that has been a major selling point of its USB Memory Stick range.

In a long-winded explanation for a relatively simple decision based on cost, Victorinox said:

“As an economic company, we are required to provide the necessary expenditures in reasonable proportion to the possible yield. For this reason we have decided to offer only pure knife products with appropriate hardware.”

The statement doesn’t spell out whether the announcement covers all the security features offered by the drives (no confirmation was received by press time) but the assumption should be that it does on the basis of the following statement.

“To this end we will discontinue our services to our web page Warning! The VeriSign software certificate for the secure.exe is only valid till 15th September 2012. We therefore strongly recommend that you create a data backup immediately,” read the email.

“Furthermore, we will stop providing any future software updates and as of September 2012 we will cease all services in this segment.”

To anyone who owns one of these drives – among the most expensive and highly-featured on the market – the decision to discontinue support and development at short notice will be shocking. The drives were launched as recently as early 2011.

Security offered on the drives includes encryption, a secure browsing mode, secure password management and a fingerprint login feature.

As well as its famous all-purpose knives, Victorinox makes watches, specialist knives, torches and licenses its name for use on luggage.  Privately held, financial data is scares but the company could have been hurt by the strong recent appreciation of the Swiss franc against currencies such as the Euro.

The company said it would continue to offer plain USB storage on its Swiss Army knives.