Secure digital signing of data

• US 20020091929A1
• Filed: 12/18/2001
• Published: 07/11/2002
• Est. Priority Date: 12/19/2000
• Status: Abandoned Application

• Current Assignee: Cypak AB
• Original Assignee: Cypak AB
• Inventors: Ehrensvard, Jakob
• Application Number:
  US10/024,576
• Publication Number:
  US 20020091929A1
• Time in Patent Office: Days
• US Class Current: 713/181
• CPC Class Codes: G06F 21/31 User authentication
• CPC Class Codes: G06F 21/64 Protecting data integrity, e.g. using checksums, certificates or signatures
• CPC Class Codes: G06Q 20/3823 combining multiple encryption tools for a transaction
• CPC Class Codes: G06Q 20/42 Confirmation, e.g. check or permission by the legal debtor of payment
• CPC Class Codes: G07F 7/1091 Use of an encrypted form of the PIN
• CPC Class Codes: H04L 2209/56 Financial cryptography, e.g. electronic payment or e-cash
• CPC Class Codes: H04L 2209/80 Wireless network architectures or network communication protocols for wireless network security H04W12/00
• CPC Class Codes: H04L 9/3226 using a predetermined code, e.g. password, passphrase or PIN network architectures or network communication protocols for supporting authentication of entities using passwords in a packet data network H04L63/083
• CPC Class Codes: H04L 9/3236 using cryptographic hash functions
• CPC Class Codes: H04L 9/3247 involving digital signatures

Abstract

A method of signing digital data, comprising the steps of subjecting the data to be signed to a message digest function to produce a digest of the data to be signed, transmitting the message digest to a small, mobile transaction device which contains a secret key and a user'"'"'s PIN code, determining whether a user'"'"'s PIN code is correct and, if it is, hashing the digest as a function of said secret key, returning the transformed message digest to a service provider, digesting and hashing the original data at the service provider using the same message digest function and secret key, and determining whether the hashed message digest at the service provider matches the hashed message digest received from the transaction device.

Claims

1. A method of signing digital data, comprising the steps of:

subjecting the data to be signed to a message digest function to produce a digest of the data to be signed;

transmitting the message digest to a small, mobile transaction device which contains a secret key and a user'"'"'s PIN code;

determining whether a user'"'"'s PIN code is correct and, if it is, hashing the digest as a function of said secret key;

returning the transformed message digest to a service provider;

digesting and hashing the original data at the service provider using the same message digest function and secret key; and

determining whether the hashed message digest at the service provider matches the hashed message digest received from the transaction device.