A method used with digital signatures when the privacy of the sender's message is extremely important and when the signing is applied to the message by a third party rather than the message creator. Before handing the message over for signing, the sender uses a blinding algorithm to scramble the message.
Signing Without Knowing the Contents
A blind signature allows a third party to sign a message and verify that the message came from a particular sender but without them knowing the message contents. See digital signature