Plans by Scotland's government to use health service records as the basis for a unique identity number to use for digital services have been criticised by rights groups.In a consultation document on "amendments to the National Health Service Central Register [NHSCR]", the government proposes that data contained on the register be shared with "certain named bodies".Specifically, the plan would see each person on the NHSCR – around 30% of the population – given what the government has called a unique citizen reference number (UCRN). This number would then be shared with up to 120 other Scottish public bodies.As part of the government's digital services plan, basic personal data are to be provided by the individual when they register for an account. These will verified against the NHSCR, at which point the UCRN will be attached to that personal data.The document states that the number would also help find missing people, people from abroad who have failed to pay for NHS treatment, and to administer new Scottish income tax powers.Currently, the sharing of data within the NHSCR is limited to Scottish local authorities and health boards.Critics have said that the database would effectively revive a failed UK identity card scheme."This would fundamentally change the relationship between citizens and the state and jeapordises our privacy," wrote Open Rights Group Scotland.However, the document state that the use of the UCRN would be undertaken in line with the Scottish Government Identity Management and Privacy Principles. The Scottish Government has also insisted it has no plans for a single identity database or cards.A spokeswoman has said that "the consultation does not extend the type of data held in the register and the information is not public".