Abstract: Cryptographically assured data structures are created to enable a single sign on and/or authentication method for securely transferring user authentication information from a first computer to a second computer to allow the user to seamlessly interact with the second computer without necessarily re-authenticating himself thereto. Thus, if a second computer trusts the methods used by a first computer to authenticate a user, then the second computer can use a cryptographically assured cookie created by the first computer to authenticate the user, without requiring the user to perform an explicit authentication step at the second computer. More particularly, a cryptographically assured cookie is made by creating a cryptographically assured voucher of a user characteristic at the first computer, and embedding the voucher into a cookie for transmission to the user's computer and hence to the second computer.

Abstract: A user inputting his access code (e.g., PIN or password) into an computing environment to access a transaction is at risk of losing the access code to an attacker who has physical or electronic access to the computing environment. To minimize this risk, the access code can be entered via a plurality of user-selectable fields, each of which takes on a series of values, the initially displayed values of which are established in a random or otherwise unpredictable manner. The user then uses a mouse, keyboard, or other input device to increment each of the selectable fields until the access code is correctly entered. Because of the randomization of the initial state, an attacker tracking the locations or number of mouse clicks or other navigation actions can not determine the finally entered access code by, e.g., computing an offset from a known initial state.

Abstract: The present invention provides an apparatus and method for confirming, timestamping, and archiving documents using telecopiers (e.g., facsimile machines). A user sends a document to a timestamping service via facsimile, which archives the transmission with a timestamp. A submission receipt, containing size-reduced images of the submission and a document identification value (DIV), is prepared and sent to the sender. The DIV can later be submitted to the timestamping service to obtain verification that the document was received at the indicated time. In addition, the invention allows for various other forms of document transmission, document identification, and timestamp verification. The invention is thus useful in any situation where it is desired to prove that a document was in existence at a given time. Other embodiments of the invention provide senders of facsimile and telecopier transmissions with confirmation that their transmissions were received successfully.