Version list for Algorithmic Research ARX CoSign Client. Don't be a Stranger! Sign up today to participate, stay informed, earn points and establish a reputation. ARX CoSign Client by Algorithmic Research Ltd. for their C:\Program Files\ARX\ARX CoSign Client\. The most recent version we have details of is: , size. Algorithmic Research's CoSign is a simple-to-use and non-tamperable digital-signature appliance that enables organizations to substitute handwritten.