Personal date/time notary device

A method for operating a user's portable token device comprising the steps of:

• a) receiving a digital value to be digitally signed by a substantially credit card-sized medium carried by a user;
• b) determining the current time from a trusted clock source embodied within said credit card sized medium;
• c) creating a digital data structure including the current time, and a value derived from information to be signed;
• d) accessing a user's stored private key which has an associated public key identified with said user;
• and
• e) digitally signing digital data said structure.

A portable user token device based system comprising:

• secure storage means for storing a user's private key, wherein said user's private key is used to perform digital signatures associated with said user and wherein said user's private key has an associated public key identified with said user;
• communication means for receiving input digital signal and emitting digital output;
• processor means for receiving said input digital signals and for performing digital signatures with the said at least one private key;
• and
• means for interfacing with a trusted date-time notary device and for coupling via said communication means date and time related signals generated by said notary device to said processor means.

A method for calibrating an on-chip clock device to compensate for individual deviation, including the steps of taking a first clock reading from a master clock;

• storing the first clock reading;
• taking a second clock reading from the master clock;
• storing the second clock reading;
• counting the number of oscillations between the master clock readings;
• determining the actual oscillation frequency using the difference between the second and first master clock readings to compute oscillations per unit time;
• storing the calculated oscillation frequency;
• and
• adjusting the output of the on-chip clock device in accordance with said calculated oscillation frequency.

A portable, token device fabricated on a portable medium so as to be readily carried or worn by a user comprising:

• a token device medium being substantially diskette-sized so as to be conveniently carried by a user and having fabricated therein:
• a secure storage device for storing a user's private key, wherein said at least one private key is used to perform digital signatures associated with said user and wherein said user's private key has an associated public key identified with said user;
• a clock for providing an indication of date and time;
• a communication port for receiving a value to be digitally signed and for emitting an output;
• a processor device coupled to said communication port and said clock for receiving said value to be digitally signed and said indication of date and time and for performing at least one digital signature with said at least one private key for output to said communication port.

A portable, token device fabricated on a portable medium and sized so as to be readily carried or worn by a user comprising:

• an item designed to be worn by a user having fabricated therein:
• a secure storage device for storing a user's private key, wherein said at least one private key is used to perform digital signatures associated with said user and wherein said user's private key has an associated public key identified with said user:
• a clock for providing an indication of date and time;
• a communication port for receiving a value to be digitally signed and for emitting an output;
• a processor device coupled to said communication port and said clock for receiving said value to be digitally signed and said indication of date and time and for performing at least one digital signature with said at least one private key for output to said communication port.