Secret key messaging

• US 6,728,378 B2
• Filed: 10/11/2001
• Issued: 04/27/2004
• Est. Priority Date: 10/13/2000
• Status: Expired due to Fees

• Current Assignee: Eversystems Information Comircio Representagco Importageo E Exportagco LTDA
• Original Assignee: Eversystems Information Comircio Representagco Importageo E Exportagco LTDA
• Inventors: Garib, Marco Aurelio
• Primary Examiner(s): HUA, LY
• Application Number:
  US09/975,848
• Publication Number:
  US 20020078351A1
• Time in Patent Office: 929 Days
• Field of Search: 380/259, 380/262, 380/281, 380/286, 705/67, 705/58, 705/76, 713/150, 713/164, 713/165, 713/170, 713/171, 713/182, 713/202, 709/206, 709/217, 709/218, 709/219, 709/238
• US Class Current: 380/259
• CPC Class Codes: G06Q 20/3674 involving authentication
• CPC Class Codes: G06Q 20/3821 Electronic credentials
• 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 2209/88 Medical equipments
• CPC Class Codes: H04L 63/0435 wherein the sending and receiving network entities apply symmetric encryption, i.e. same key used for encryption and decryption cryptographic mechanisms or cryptographic arrangements for symmetric key encryption H04L9/06
• CPC Class Codes: H04L 63/083 using passwords cryptographic mechanisms or cryptographic arrangements for entity authentication using a predetermined code H04L9/3226
• CPC Class Codes: H04L 63/123 received data contents, e.g. message integrity
• CPC Class Codes: H04L 9/0822 using key encryption key
• 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

The invention provides computer-enabled methods and systems for the secure transmission and platform-independent receipt and decryption of encrypted messages. According to the invention messages are encrypted by a symmetric encryption algorithm using a secret key that is, or is based on, a password known to the intended recipient. The recipient is also sent a computer program which upon input of the correct password, uses the password to generate the secret key, or alternatively, uses the password as the secret key. The program then uses the secret key to decrypt the encrypted message. The invention further provides for ensuring the integrity and authenticity of sent and received messages. The communications medium over which messages are sent according to the invention may be a communications network such as the Internet and the messages may be electronic mail messages and MIME messages. The invention also provides for the secure delivery of statement and transaction information pertaining to an account.

Claims

1. A method for transmitting and receiving encrypted messages, the method comprising the steps of:

(1) providing a password to the intended recipient of a message, wherein the password is mutually agreed upon in advance by a sender and the recipient;

(2) preparing a message to be sent to the recipient;

(3) encrypting the message with a symmetric encryption algorithm wherein a secret key for the symmetric encryption algorithm is the password;

(4) sending the recipient the encrypted message, wherein the encrypted message does not include the password; and

(5) sending the recipient a set of computer instructions instructing at least one computer processor of a device the recipient uses to access the encrypted message to perform the steps of;

(a) accepting password input from the recipient; and

(b) decrypting the encrypted message with the symmetric encryption algorithm using the password inputted in step (a) as the symmetric key.

6. The method according to any one of claims 1-5 wherein the step of sending the recipient the encrypted message and the step of sending the recipient a set of computer instructions comprise sending the recipient the encrypted message and the set of computer instructions as a single combined communication.

7. The method according to claim 6 wherein the encrypted message is an encrypted markup-language document.

8. The method according to any one of claims 1-5 wherein the step of sending the recipient the encrypted message and the step of sending the recipient a set of computer instructions comprise sending the recipient the encrypted message and the set of computer instructions as parts of a single MIME message.

9. The method according to claim 8 wherein the encrypted message is an encrypted markup-language document.

10. The method according to claim 9 wherein the set of computer instructions sent to the recipient are embedded in a mark-up language document.

11. The method according to claim 9 wherein the markup language is selected from the group consisting of hypertext markup language (HTML), extensible markup language (XML), wireless markup language (WML), and forms markup language (FML).

12. The method according to claim 11 wherein the set of computer instructions sent to the recipient are in a form selected from the group consisting of scripts and applets.

13. The method according to claim 12 wherein the medium for sending is an electronic communications network.

14. The method according to claim 13 wherein the electronic communications network is the Internet.

15. The method according to claim 14 wherein the message is an electronic mail message.

16. The method according to claim 13 wherein the electronic communications network is a wireless communications network.

17. The method according to any one of claims 1-5 wherein the intended recipient is an entity authorized to receive account information pertaining to a financial account, the method further comprising the step of:

periodically scanning the account information; and

wherein the step of preparing a message further comprises preparing a message in response to the scanning wherein the message comprises at least a subset of the scanned account information.

18. The method according to claim 17 wherein the message comprises a summary of account information.

19. The method according to claim 17 wherein the entity is selected from the group consisting of the holders of the financial account and authorized agents thereof.

20. The method according to any one of claims 1-5 wherein the intended recipient is an entity authorized to receive account information pertaining to a financial account, wherein the step of preparing a message is in response to the occurrence of a transaction in the account, and wherein the message comprises information related to the transaction.

21. The method according to claim 20 wherein the intended recipient is selected from the group consisting of the holders of the financial account and authorized agents thereof.

22. The method according to any one of claims 1-5 wherein the intended recipient is an entity authorized to receive medical information pertaining to at least one patient and wherein the message comprises the medical information.

23. The method according to claim 22 wherein the intended recipient is selected from the group consisting of the patient and medical personnel.

24. The method according to any one of claims 1-5 further comprising the steps of:

generating a digital signature comprising an encrypted message hash value of the prepared message wherein a hash value of the prepared message is encrypted using a private key of the sender with a public-key encryption algorithm;

sending the digital signature to the recipient; and

sending the recipient a second set of computer instructions instructing at least one computer processor of a device the recipient uses to access the encrypted message to perform the steps of;

(a) decrypting the digital signature using a public key of the sender with the public-key encryption algorithm to generate the message hash value

(b) generating a message hash value of the symmetrically decrypted message using the same hashing algorithm used to generate the message hash value for the digital signature

(c) comparing the message hash value generated in (a) with the message hash value generated in (b) to verify the integrity of the message received by the recipient.

25. The method according to any one of claims 1-5 wherein at least part of the information content of a message is selectable by the intended recipient.

2. A method for transmitting and receiving encrypted messages, the method comprising the steps of:

(1) providing a password to the intended recipient of the message;

(2) preparing a message to be sent to the recipient;

(3) applying a hashing algorithm to the message to generate a message hash value;

(4) encrypting the message and the message hash value with a symmetric encryption algorithm wherein a secret key for the symmetric encryption algorithm is the password;

(5) sending the recipient the encrypted message and encrypted message hash value; and

(6) sending the recipient a set of computer instructions instructing at least one computer processor of a device the recipient uses to access the encrypted message to perform the steps of;

(a) accepting password input from the recipient;

(b) decrypting the encrypted message and encrypted message hash value with the symmetric encryption algorithm using the password inputted in step (a) as the symmetric key;

(c) applying the hashing algorithm to the decrypted message obtained in step (b) to generate a message hash value; and

(d) comparing the message hash value obtained in step (c) with the message hash value obtained in step (3) to verify the integrity of the message received by the recipient.

26. The method according to any one of claims 2, 4 and 5 further comprising the steps of:

combining the prepared message and message hash value into a unit, wherein the step of encrypting the message and the message hash value encrypts the unit;

generating a digital signature comprising an encrypted hash value of the symmetrically encrypted unit encrypted wherein the hash value is encrypted using a private key of the sender with a public-key encryption algorithm;

sending the digital signature to the recipient; and

sending the recipient a set of computer instructions instructing at least one computer processor of a device the recipient uses to access the encrypted message to perform the steps of;

(a) decrypting the digital signature using a public key of the sender with the public-key encryption algorithm to generate the hash value for the symmetrically encrypted unit;

(b) generating a hash value of the symmetrically encrypted unit using the same hashing algorithm used to generate the digital signature; and

(c) comparing the hash value generated in (a) with the value generated in (b) to verify the integrity of the message received by the recipient.

27. The method according to claim 26 wherein the unit comprises a MIME message.

28. The method according to claim 26 wherein the encrypted unit is part of a MIME message.

3. A method for transmitting and receiving encrypted messages, the method comprising the steps of:

(1) providing a password to the intended recipient of the message;

(2) applying a first hashing algorithm to the password to generate a password hash value;

(3) preparing a message to be sent to the recipient;

(4) encrypting the message with a symmetric encryption algorithm wherein a secret key for the symmetric encryption algorithm is the password hash value;

(5) sending the recipient the encrypted message; and

(6) sending the recipient a set of computer instructions instructing at least one computer processor of a device the recipient uses to access the encrypted message to perform the steps of;

(a) accepting password input from the recipient;

(b) applying the first hashing algorithm to the password input of (a) to generate the password hash value; and

(c) decrypting the encrypted message with the symmetric encryption algorithm using the password hash value generated in step (b) as the symmetric key.

4. A method for transmitting and receiving encrypted messages, the method comprising the steps of:

(1) providing a password to the intended recipient of the message;

(2) applying a first hashing algorithm to the password to generate a password hash value;

(3) preparing a message to be sent;

(4) applying a second hashing algorithm to the message to generate a message hash value;

(5) encrypting the message and the message hash value with a symmetric encryption algorithm using the password hash value as a symmetric key;

(6) sending the recipient the encrypted message and the encrypted message hash value to the recipient; and

(7) sending the recipient a set of computer instructions instructing at least one computer processor of a device the recipient uses to access the encrypted message to perform the steps of;

(a) accepting password input from the recipient;

(b) applying the first hashing algorithm to the password input of (a) to generate the password hash value;

(c) decrypting the encrypted message with the symmetric encryption algorithm using the password hash value generated in step (b) as the symmetric key;

(d) decrypting the encrypted message hash value with the symmetric encryption algorithm using the password hash value generated in step (b) as a symmetric key;

(e) applying the second hashing algorithm to the decrypted message to generate a hash value; and

(f) comparing the message hash value obtained in step (d) with the message hash value obtained in step (e) to verify the integrity of the message received by the recipient.

5. The method according to claim 4 wherein the first hashing algorithm and the second hashing algorithm are the same.

29. A system for transmitting and receiving encrypted messages, the system comprising:

(1) preparing means for preparing a message to be sent to the recipient;

(2) encrypting means for encrypting the message with a symmetric encryption algorithm wherein a secret key for the symmetric encryption algorithm is a password mutually agreed upon in advance by a sender and the intended recipient;

(3) sending means for sending the recipient;

(a) the encrypted message, wherein the encrypted message does not include the password, and

(b) a set of computer instructions for instructing at least one computer processor of a device the recipient uses to access the encrypted message to perform the steps of;

(i) accepting password input from the recipient;

(ii) decrypting the encrypted message with the symmetric encryption algorithm using the password inputted in step (i) as the symmetric key.

30. The system according to claim 29 further comprising:

providing means for providing the password to the intended recipient of a message.

40. A method of decrypting a message comprising the step of:

on a device comprising input means, at least one computer processor and computer readable memory, wherein an encrypted message and a set of computer instructions according to any one of claims 29, 31, 33 and 35 is stored, executing the set of computer instructions and inputting a password to decrypt the message.

41. The system according to any one of claims 29, 31, 33 and 35 further comprising:

accounting means for accounting for the sent message in an account tracking sent messages.

42. The system according to any one of claims 29, 31, 33 and 35, wherein the message is an electronic mail message.

43. The system according to claim 42, wherein the set of computer instructions sent to the recipient by the sending means are in a form selected from the group consisting of scripts and applets.

44. The system according to any one of claims 29, 31, 33 and 35, wherein the set of computer instructions sent to the recipient by the sending means are in a form selected from the group consisting of scripts and applets.

31. A system for transmitting and receiving encrypted messages, the system comprising:

(1) preparing means for preparing a message to be sent to the recipient;

(2) hashing means for applying a hashing algorithm to the message to generate a message hash value;

(3) encrypting means for encrypting the message and the message hash value with a symmetric encryption algorithm wherein a secret key for the symmetric encryption algorithm is a password known to the intended recipient;

(4) sending means for sending the recipient;

(a) the encrypted message and encrypted message hash value, and

(b) a set of computer instructions for instructing at least one computer processor of a device the recipient uses to access the encrypted message to perform the steps of;

(i) accepting password input from the recipient;

(ii) decrypting the encrypted message and encrypted message hash value with the symmetric encryption algorithm using the password inputted in step (i) as the symmetric key;

(iii) applying the hashing algorithm to the decrypted message obtained in step (ii) to generate a message hash value;

(iv) comparing the message hash value obtained in step (iii) with the message hash value obtained in step (ii) to verify the integrity of the message received by the recipient.

32. The system according to claim 31 further comprising:

providing means for providing the password to the intended recipient of the message.

37. The system according to any one of claims 31 and 34-36 further comprising:

combining means for combining the prepared message and message hash value into a unit,

wherein the encryption means encrypts the message and the message hash value by encrypting the unit using the symmetric algorithm to obtain an encrypted unit, and

wherein the sending means sends the encrypted combined message and message hash value by sending the encrypted unit;

digital signature generating means for generating a digital signature comprising a hash value of the symmetrically encrypted unit encrypted using a private key of the sender with a public-key encryption algorithm; and

sending means for sending the recipient;

(a) the digital signature, and

(b) a set of computer instructions for instructing at least one computer processor of a device the recipient uses to access the encrypted message to perform the steps of;

(i) decrypting the digital signature using a public key of the sender with the public-key encryption algorithm to generate the hash value for the symmetrically encrypted unit;

(ii) generating a hash value of the symmetrically encrypted unit using the same hashing algorithm used to generate the digital signature; and

(iii) comparing the hash value generated in (i) with the value generated in (ii) to verify the integrity of the message received by the recipient.

38. The system according to claim 37 wherein the unit comprises a MIME message.

39. The method according to claim 37 wherein the encrypted unit is part of a MIME message.

33. A system for transmitting and receiving encrypted messages, the system comprising:

(1) preparing means for preparing a message to be sent to the recipient;

(2) encrypting means for encrypting the message with a symmetric encryption algorithm wherein a secret key for the symmetric encryption algorithm is a password hash value generated from a password known to the intended recipient;

(3) sending means for sending the recipient;

(a) the encrypted message, and

(b) a set of computer instructions for instructing at least one computer processor of a device the recipient uses to access the encrypted message to perform the steps of;

(i) accepting password input from the recipient;

(ii) applying the password hashing algorithm to the password input of (i) to generate the password hash value; and

(iii) decrypting the encrypted message with the symmetric encryption algorithm using the password hash value generated in step (ii) as the symmetric key.

34. The system according to claim 33 further comprising

providing means for providing the password to the intended recipient of the message; and

a password hashing means for applying a password hashing algorithm to the password to generate a password hash value.

35. A system for transmitting and receiving encrypted messages, the system comprising:

(1) preparing means for preparing a message to be sent;

(2) message hashing means for applying a hashing algorithm to the message to generate a message hash value;

(3) encrypting the message and the message hash value with a symmetric encryption algorithm using a hash value generated from a password known to the intended recipient as a symmetric key; and

(4) sending the recipient;

(a) the encrypted message and the encrypted message hash value, and

(b) a set of computer instructions instructing at least one computer processor of a device the recipient uses to access the encrypted message to perform the steps of;

(i) accepting password input from the recipient;

(ii) applying the password hashing algorithm to the password input of (i) to generate the password hash value;

(iii) decrypting the encrypted message with the symmetric encryption algorithm using the password hash value generated in step (ii) as the symmetric key;

(iv) decrypting the encrypted message hash value with the symmetric encryption algorithm using the password hash value generated in step (ii) as a symmetric key;

(v) applying the message hashing algorithm to the decrypted message to generate a hash value; and

(vi) comparing the message hash value obtained in step (iv) with the message hash value obtained in step (v) to verify the integrity of the message received by the recipient.

36. The system according to claim 35 further comprising:

providing means for providing the password to the intended recipient of the message; and

password hashing means for applying a password hashing algorithm to the password to generate a password hash value.

45. A computer readable memory instructing at least one computer to perform the steps of:

(1) preparing a message to be sent to an intended recipient;

(2) encrypting the message with a symmetric encryption algorithm wherein a secret key for the symmetric encryption algorithm is a password known to the intended recipient, wherein the password is mutually agreed upon in advance by a sender and the recipient;

(3) sending the recipient;

(a) the encrypted messages wherein the encrypted message does not include the password, and

(b) a set of computer instructions for instructing at least one computer processor of a device the recipient uses to access the encrypted message to perform the steps of;

(i) accepting password input from the recipient; and

(ii) decrypting the encrypted message with the symmetric encryption algorithm using the password inputted in step (i) as the symmetric key.

46. The memory according to claim 45 further instructing at least one computer to perform the step of:

providing the password to the intended recipient of a message.

53. A computer readable memory comprising the set of computer instructions sent to the recipient in any one of claims 45, 47, 49 and 51.

56. The computer readable memory according to any one of claims 45, 47, 49 and 51 further instructing at least one computer to perform the step of:

accounting for the sent message in an account tracking sent messages.

57. The computer readable memory according to any one of claims 45, 47, 49 and 51 wherein the message is an electronic mail message.

58. The computer readable memory according to claim 57, wherein the set of computer instructions sent to the recipient are in a form selected from the group consisting of scripts and applets.

59. The computer readable memory according to any one of claims 45, 47, 49 and 51, wherein the set of computer instructions sent to the recipient are in a form selected from the group consisting of scripts and applets.

47. A computer readable memory instructing at least one computer to perform the steps of:

(1) preparing a message to be sent to an intended recipient;

(2) applying a hashing algorithm to the message to generate a message hash value;

(3) encrypting the message and the message hash value with a symmetric encryption algorithm wherein a secret key for the symmetric encryption algorithm is a password known to the intended recipient;

(4) sending the recipient;

(a) the encrypted message and the encrypted message hash value, and

(b) a set of computer instructions for instructing at least one computer processor of a device the recipient uses to access the encrypted message to perform the steps of;

(i) accepting password input from the recipient;

(ii) decrypting the encrypted message and encrypted message hash value with the symmetric encryption algorithm using the password inputted in step (i) as the symmetric key;

(iii) applying the hashing algorithm to the decrypted message obtained in step (ii) to generate a message hash value; and

(iv) comparing the message hash value obtained in step (iii) with the message hash value obtained in step (2) to verify the integrity of the message received by the recipient.

48. The computer readable memory according to claim 47 further instructing at least one computer to perform the steps of:

providing the password to the intended recipient of the message.

54. The computer readable memory according to any one of claims 47, 48, 51 and 52 further instructing at least one computer to perform the steps of:

combining the prepared message and message hash value into a unit,

wherein the step of encrypting encrypts the message and the message hash value by encrypting the unit using the symmetric algorithm, and

wherein the step of sending sends the encrypted message and the encrypted message hash value by sending the unit;

generating a digital signature comprising a hash value of the symmetrically encrypted unit encrypted using a private key of the sender with a public-key encryption algorithm; and

sending the recipient;

(a) the digital signature, and

(b) a set of computer instructions for instructing at least one computer processor of a device the recipient uses to access the encrypted message to perform the steps of;

(i) decrypting the digital signature using the public key of the sender with the public-key encryption algorithm to generate the hash value for the symmetrically encrypted unit;

(ii) generating a hash value of the symmetrically encrypted unit using the same hashing algorithm used to generate the digital signature; and

(iii) comparing the hash value generated in (i) with the hash value generated in (ii) to verify the integrity of the encrypted unit received by the recipient.

55. A computer readable memory comprising the set of computer instructions sent to the recipient in claim 54.

49. A computer readable memory instructing at least one computer to perform the steps of:

(1) preparing a message to be sent to an intended recipient;

(2) encrypting the message with a symmetric encryption algorithm wherein a secret key for the symmetric encryption algorithm is a password hash value generated from a password known to the intended recipient;

(3) sending the recipient;

(a) the encrypted message

(b) a set of computer instructions for instructing at least one computer processor of a device the recipient uses to access the encrypted message to perform the steps of;

(i) accepting password input from the recipient;

(ii) applying the password hashing algorithm to the password input of (i) to generate the password hash value;

(iii) decrypting the encrypted message with the symmetric encryption algorithm using the password hash value generated in step (ii) as the symmetric key.

50. The computer readable memory according to claim 49 further instructing at least one computer to perform the steps of:

providing the password to the intended recipient of the message; and

applying a password hashing algorithm to the password to generate a password hash value.

51. A computer readable memory instructing at least one computer to perform the steps of:

(1) preparing a message to be sent to an intended recipient;

(2) applying a hashing algorithm to the message to generate a message hash value;

(3) encrypting the message and the message hash value with a symmetric encryption algorithm using a hash value generated from a password known to the intended recipient as a symmetric key; and

(4) sending the recipient;

(a) the encrypted message and the encrypted message hash value, and

(b) a set of computer instructions instructing at least one computer processor of a device the recipient uses to access the encrypted message to perform the steps of;

(i) accepting password input from the recipient;

(ii) applying the password hashing algorithm to the password input of (i) to generate the password hash value;

(iii) decrypting the encrypted message with the symmetric encryption algorithm using the password hash value generated in step (ii) as the symmetric key;

(iv) decrypting the encrypted message hash value with the symmetric encryption algorithm using the password hash value generated in step (ii) as a symmetric key;

(v) applying the message hashing algorithm to the decrypted message to generate a hash value; and

(vi) comparing the message hash value obtained in step (iv) with the message hash value obtained in step (v) to verify the integrity of the message received by the recipient.

52. The computer readable memory according to claim 51 instructing at least one computer to perform the steps of:

providing a password to the intended recipient of the message; and

applying a password hashing algorithm to the password to generate a password hash value.