Back to results
US 6,959,387 B2Granted
Method and apparatus for verifying secure document timestamping
AssigneeWalker Digital, LLC
InventorsJay S. Walker, Bruce Schneier, James A. Jorasch, Dean P. Alderucci
Life of this patent
Estimating the term…
Abstract
According to one embodiment of the invention, a method is provided for receiving a timestamp from a caller via a telephone connection; receiving a device identifier from the caller, in which the device identifier identifies a device; determining a cryptographic key based on the device identifier; determining an indication of a time based on the timestamp and the cryptographic key; providing the indication of the time to the caller; determining an account; and charging a fee to the account.
Claims24
A method comprising:
- receiving a timestamp from a caller via a telephone connection;
- receiving a device identifier from the caller, in which the device identifier identifies a device;
- determining a cryptographic key based on the device identifier;
- determining a representation of a time based on the timestamp and the cryptographic key;
- providing the representation of the time to the caller;
- determining an account;
- and
- charging a fee to the account.
5 more elements
A method comprising:
- receiving a sequence of DTMF signals from a caller via a telephone connection;
- determining a timestamp based on the DTMF signals;
- receiving a device identifier from the caller, in which the device identifier identifies a device;
- determining a cryptographic key based on the device identifier;
- determining a representation of a time based on the timestamp and the cryptographic key;
- providing the representation of the time to the caller;
- determining an account;
- and
- charging a fee to the account.
6 more elements
A method comprising:
- receiving a timestamp from a timestamp recipient via an Internet connection;
- receiving a device identifier via the Internet connection, in which the device identifier identifies a device;
- determining a cryptographic key based on the device identifier;
- determining a representation of a time based on the timestamp and the cryptographic key;
- providing the representation of the time to the timestamp recipient via the Internet connection;
- determining an account;
- and
- charging a fee to the account.
5 more elements
Dependencies are inferred from the claim text.