Editing Security token (section)

== Digital signature ==

Trusted as a regular hand-written signature, the [[digital signature]] must be made with a private key known only to the person authorized to make the signature. Tokens that allow secure on-board generation and storage of private keys enable secure digital signatures, and can also be used for user authentication, as the private key also serves as a proof of the user's identity.

For tokens to identify the user, all tokens must have some kind of number that is unique. Not all approaches fully qualify as [[digital signature]]s according to some national laws.{{Citation needed|date=February 2007}} Tokens with no on-board keyboard or another [[user interface]] cannot be used in some [[Digital signature|signing]] scenarios, such as confirming a bank transaction based on the bank account number that the funds are to be transferred to.