Electronic negotiable documents

• US 7,505,945 B2
• Filed: 12/20/2000
• Issued: 03/17/2009
• Est. Priority Date: 02/08/1995
• Status: Expired due to Fees

• Current Assignee: Cryptomathic A/S (Infineon Technologies AG)
• Original Assignee: Cryptomathic A/S (Infineon Technologies AG)
• Inventors: Landrock, Peter
• Primary Examiner(s): Retta; Yehdega
• Application Number:
  US09/747,511
• Publication Number:
  US 20010016838A1
• Time in Patent Office: 3,009 Days
• Field of Search: 705/69, 705/41, 705/54, 705/52, 705/80, 705/51, 283/72, 38/40
• US Class Current: 705/80
• CPC Class Codes: G06F 21/6209 to a single file or object, e.g. in a secure envelope, encrypted and accessed using a key, or with access control rules appended to the object itself
• CPC Class Codes: G06F 21/64 Protecting data integrity, e.g. using checksums, certificates or signatures
• CPC Class Codes: G06F 2221/2153 Using hardware token as a secondary aspect
• CPC Class Codes: G06Q 10/10 Office automation; Time management
• CPC Class Codes: G06Q 20/04 Payment circuits
• CPC Class Codes: G06Q 20/0425 the cheque being electronic only
• CPC Class Codes: G06Q 20/06 Private payment circuits, e.g. involving electronic currency used among participants of a common payment scheme
• CPC Class Codes: G06Q 20/3825 Use of electronic signatures
• CPC Class Codes: G06Q 50/18 Legal services
• CPC Class Codes: G06Q 50/188 Electronic negotiation
• CPC Class Codes: G07F 7/1016 Devices or methods for securing the PIN and other transaction-data, e.g. by encryption arrangements for secret communication, see H04L9/00
• CPC Class Codes: H04L 2209/56 Financial cryptography, e.g. electronic payment or e-cash
• CPC Class Codes: H04L 2209/608 Watermarking
• CPC Class Codes: H04L 9/3247 involving digital signatures
• CPC Class Codes: H04L 9/3263 involving certificates, e.g. public key certificate [PKC] or attribute certificate [AC]; Public key infrastructure [PKI] arrangements network architectures or network communication protocols for supporting authentication of entities using certificates in a packet data network H04L63/0823
• CPC Class Codes: H04L 9/3297 involving time stamps, e.g. generation of time stamps

Abstract

A method of issuing an electronic negotiable document (END) comprising: creating as data an END and storing this in a tamper-resistant document carrier, the document carrier containing a unique public-secret key pair for signing and verifying and a unique document carrier identifier; signing the unique document-carrier identifier, the END and an END identifier using the secret key of the public-secret key pair and storing the result in the document carrier.

Claims

1. A method of electronically negotiating an electronic negotiable document, transferred along a chain of sellers and buyers, wherein said electronic negotiable document has a value which is an amount of money or quantity of goods, and wherein said seller is not a bank, the method comprising:

issuing from a trusted supplier said seller with seller tamper-resistant document carrier hardware, said seller tamper-resistant document carrier hardware having its own public-secret key pair, and wherein said secret key is not accessible to said seller, said tamper-resistant document carrier hardware bearing said electronic negotiable document and a signature calculated using said secret key;

issuing from a trusted supplier said buyer with buyer tamper-resistant document carrier hardware, said buyer tamper-resistant document carrier hardware having its own public-secret key pair, and wherein said secret key is not accessible to said buyer;

transferring said electronic negotiable document from said seller tamper-resistant document carrier hardware to said buyer tamper-resistant document carrier hardware;

splitting the original value of said electronic negotiable document electronically in said buyer tamper-resistant document carrier hardware by creating two or more split versions of said electronic negotiable document each with a new sequence number;

inputting to said buyer tamper-resistant document carrier hardware, now acting as a seller tamper-resistant document carrier hardware, values defining values of each new said split version, wherein each new said split version comprises the signature of the original electronic negotiable document, and wherein each new said split version has a value such that the sum of the values of said two or more split versions adds up to said value of said original electronic negotiable document;

digitally signing said split versions using said secret key of said buyer tamper-resistant document carrier hardware acting as a seller tamper-resistant document carrier hardware to generate a splitting signature; and

transferring said two or more split versions separately to one or more further buyers without the involvement of a trusted third party;

wherein each of said further buyers is able to transfer a said split version to one or more buyers in the chain.

2. The method as claimed in claim 1 wherein said seller and said buyer tamper-resistant document carrier hardware each have a document carrier identifier, and wherein each said document carrier identifier is signed by a said secret key.

3. The method as claimed in claim 1 wherein said seller tamper-resistant document carrier hardware bears an issuing signature, and wherein said transferring includes transferring said issuing signature from said seller tamper-resistant document carrier hardware to said buyer tamper-resistant document carrier hardware.

4. The method as claimed in claim 3 further comprising deleting said issuing signature after said transferring.