The social insurance number is an identifier that provides access to federal programs and services, as well as to income and tax systems. In the case involving the federal government, with respect to benefits, for example, my colleague explained that at the Canada Revenue Agency you have to ask an additional, secret question to identify individuals, such as the amount entered on a certain line of the tax return. In the case of employment insurance, participants are given a program access code, and must give two digits of this code in order to access private information related to the employment insurance program.
The social insurance number is an identifier, but it is accompanied by other questions to validate the identity of the person with whom we do business.