Reliable document authentication system

• US 4,853,961 A
• Filed: 12/18/1987
• Issued: 08/01/1989
• Est. Priority Date: 12/18/1987
• Status: Expired due to Term

• Current Assignee: Pitney Bowes Incorporated Walter H Wheeler Jr Drive Stamford CT A Corporation
• Original Assignee: Pitney Bowes Incorporated (Böwe Systec AG)
• Inventors: Pastor, Jose
• Primary Examiner(s): CANGIALOSI, SALVATORE A
• Application Number:
  US07/136,251
• Time in Patent Office: 592 Days
• Field of Search: 380/21, 380/30, 380/25
• US Class Current: 713/176
• CPC Class Codes: B07C 1/00 Measures preceding sorting according to destination
• CPC Class Codes: G06F 21/606 by securing the transmission between two devices or processes
• CPC Class Codes: G06F 21/64 Protecting data integrity, e.g. using checksums, certificates or signatures
• CPC Class Codes: G06F 2221/2107 File encryption
• CPC Class Codes: G06F 2221/2147 Locking files
• CPC Class Codes: G07B 17/00733 Cryptography or similar special procedures in a franking system
• CPC Class Codes: G07B 2017/00758 Asymmetric, public-key algorithms, e.g. RSA, Elgamal
• CPC Class Codes: G07B 2017/00854 Key generation
• CPC Class Codes: G07B 2017/0087 Key distribution
• CPC Class Codes: G07B 2017/00895 Key verification, e.g. by using trusted party
• CPC Class Codes: G07B 2017/00911 Trusted party
• CPC Class Codes: G07F 7/08 by coded identity card or credit card or other personal identification means without personal verification means G07F7/02
• 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: G07F 7/12 Card verification

Abstract

A system for reliably authenticating a document includes a device having a decryption key therein that, upon application to information provided by a user, reveals not only a plain text message indicating the source of the authentication but, in addition, provides the decryption key for use with the information provided by the mailer.

Claims

1. A method for authenticating documents sent by a user to an authentication service, comprising the steps of:

(a) generation by a third party of a first pair of encryption keys E₁, D₁ and at least a second pair of encryption keys E_i, D_i ;

(b) said third party;

(b1) maintaining said key E₁ in privacy;

(b2) providing said key E_i to said user;

(b3) providing said key D₁ to said authentication service;

(b4) encrypting a message M with said key E₁, said message M comprising said key Di;

(b5) providing said encrypted message E₁ [M] to said user;

(c) said user;

(c1) incorporating said encrypted message E₁ [M] into said document;

(c2) encrypting additional information P with said key E_i ;

(c3) incorporating said additional encrypted information E_i [P] into said document; and

,

(c4) delivering said document to said authentication service; and

(d) said authentication service;

(d1) decrypting said encrypted message E₁ [M] with said key D₁ to obtain said key D_i ; and

(d2) decrypting said additional encrypted information E_i [P] with said key D_i.

2. The method of claim 1 wherein said third party further encrypts said encrypted message E₁ [M] with said key D_i and provides said user with said further encrypted message D_i [E₁ [M]] to said user, said user decrypting said further encrypted message D_i [E₁ [M]] with said key Ei to obtain said encrypted message E₁ [M].

3. The method of claim 2 wherein said message M further comprises a certification message M₁, said certification message M₁ including information relating to said document, such as the identity of said user.

4. The method of claim 3 wherein said authentication service relies, at least in part, upon said certification message M₁ to authenticate said document.

5. The method of claim 1 wherein said user is a mailer, said authentication service is a mail delivery service, and said document is a mailing document.

6. The method of claim 1 wherein said keys E_i, D_i are altered from time to time by said third party so as to increase the security of the system.

7. A system for use by a third party to authenticate documents sent by a user to a third party, comprising:

(a) means for generating a first pair of encryption keys E₁, D₁ and at least a second pair of encryption keys E_i, D_i ;

(b) means for providing said key E_i to said user;

(c) means for providing said key D₁ to said authentication service;

(d) means for encrypting a message M with said key E₁ ;

said message comprising said key D_i ; and

(e) means for providing said encrypted message E₁ [M] to said user.

8. The system of claim 7 wherein said encrypting means further includes means for further encrypting said encrypted message E₁ [M] with said key Di.

9. The system of claim 8 wherein said message M further comprises a certification message M₁ including information relating to said document, such as the identity of said user.

10. The system of claim 7 wherein said user is a mailer, said authentication service is a mail delivery service, and said document is a mailing document.

11. The system of claim 7 further comprising means for altering said key E_i, D_i from time to time.

17. The system of claim 8 wherein said authentication service is a mail service, said document is a mailing document and said information P is included in plain text on said document.

12. A system for use by a user to authenticate documents sent by said user to an authentication service, comprising:

(a) means for receiving a key E_i from a third party, said key E_i forming part of a pair of encryption/decryption keys E_i, D_i ;

(b) means for receiving a message E₁ [M] encrypted with a key E₁, said message M comprising said key D_i ;

(c) means for incorporating said encrypted message E₁ [M] into said document;

(d) means for encrypting additional information P with said key E_i ; and

,

(e) means for incorporating said encrypted additional information E_i [P] into said document.

13. The system of claim 12 wherein said encrypted message E₁ [M] is further encrypted with said key D_i and receiving means further includes means for decrypting said further encrypted message D_i [E₁ [M]] with said key D_i.

14. The system of claim 12 wherein said user is a mailer, said authentication service is a mail delivery service, and said document is a mailing document.

15. The system of claim 12 further comprising means for receiving an altered key E_i from time to time.

16. A system for use by an authentication service to authenticate a document said document comprising an encrypted message E₁ [M], said encrypted message E₁ [M] comprising a key D_i and said document further comprising additional information encrypted with a key E_i, E_i [P], said keys forming an encryption decryption pair E_i, D_i, said system comprising:

(a) means for storing a decryption key D₁, said key D₁ forming an encryption/decryption pair E₁, D₁ with said key E₁ ;

(b) means for decrypting said encrypted message E₁ [M] to obtain said key D_i ;

(c) means for decrypting said additional encrypted information E_i [P] to obtain information P.