Glasgow firm Tradeforms Scotland has tweaked its Infosafe product, which is currently used to provide a tamper-proof way of keeping students' identities secret from exam markers.

"It's innovative, but very simple," said product development manager Tommy Connell. "It's designed to  make sure that it can't be tampered with or viewed by anyone until it gets to the election official."

A voter casts their vote before folding over a perforated strip back-printed to prevent show-through onto a self adhesive strip on the ballot paper concealing their vote.

Any attempt to modify or read the strip then becomes immediately apparent.

So far the firm has yet to sign up any users for Infosafe's use in ballot papers, but 20 universities use the product, developed by Connell and his father Tom.