A security token is a peripheral device used to gain access to an electronically restricted resource. The token is used in addition to, or in place of, a password. Examples of security tokens include wireless keycards used to open locked doors, a banking token used as a digital authenticator for signing in to online banking, or signing a transaction such as a wire transfer.

Online banking, also known as internet banking, virtual banking, web banking or home banking, is a system that enables customers of a bank or other financial institution to conduct a range of financial transactions through the financial institution's website or mobile app. Since the early 2000s this has become the most common way that customers access their bank accounts.