Symmetrically-secured electronic communication system

• US 6,311,171 B1
• Filed: 07/11/1997
• Issued: 10/30/2001
• Est. Priority Date: 07/11/1997
• Status: Expired due to Term

• Current Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Original Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Inventors: Dent, Paul W.
• Primary Examiner(s): Trammell, James P.
• Assistant Examiner(s): Dixon, Thomas A.
• Application Number:
  US08/893,498
• Time in Patent Office: 1,572 Days
• Field of Search: 705/37, 705/44, 705/64, 705/69, 705/66, 380/23, 380/24, 380/30, 235/379, 235/380
• US Class Current: 705/64
• CPC Class Codes: G06Q 20/02 involving a neutral party, e.g. certification authority, notary or trusted third party [TTP]
• CPC Class Codes: G06Q 20/382 insuring higher security of transaction
• CPC Class Codes: G06Q 20/3829 involving key management
• CPC Class Codes: H04L 2209/56 Financial cryptography, e.g. electronic payment or e-cash
• CPC Class Codes: H04L 9/321 involving a third party or a trusted authority

Abstract

Techniques for providing secure electronic communications, for example communications relating to asset trading, are described. Symmetrical usage of encryption keys by first and second parties engaged in these communications provide enhanced security. The establishment of trusted registries, e.g., databases, which include electronic asset representations, allow for trades to be enacted without significant human intervention.

Claims

1. A method for electronic communication between a first and second party comprising the steps of:

retrieving, from a database, a doubly-encrypted record;

decrypting, by said first party, said doubly encrypted record using said first party'"'"'s secret key to generate a singly encrypted record;

re-encrypting, by said first party, said singly encrypted record using said second party'"'"'s public key;

transmitting said re-encrypted record to said second party;

decrypting, by said second party, said re-encrypted record using said second party'"'"'s secret key to generate said singly encrypted record; and

decrypting, by said second party, said singly encrypted record using a third party'"'"'s public key.

2. The method of claim 1, wherein said step of transmitting further comprises the step of:

transmitting said re-encrypted record over an air interface.

3. The method of claim 1, wherein said third party is a guaranteeing institution.

4. An apparatus comprising:

a memory device which stores doubly encrypted bit patterns associated with monetary denominations; and

a device for for receiving said doubly encrypted bit patterns over a communications channel and for storing said doubly encrypted bit patterns in said memory device,

wherein said communications channel optionally employs a third communications encryption, and said device deciphers said third communications encryption to obtain said doubly encrypted bit patterns, and

wherein said doubly encrypted bit patterns are encrypted once using a first party'"'"'s secret key and once using a public key associated with said memory device.

5. The apparatus of claim 4, wherein said receiving/storing device and memory device are housed within a card.

6. The apparatus of claim 4, wherein said receiving/storing device and memory device are housed within a mobile phone.

7. A method for electronically transferring money between an electronic wallet and a point-of-sale terminal comprising the steps of:

storing, in said electronic wallet, doubly encrypted bit patterns representing said money;

decrypting, in said electronic wallet, at least one of said doubly encrypted bit patterns to generate at least one singly encrypted bit pattern;

re-encrypting, in said electronic wallet, said at least one singly encrypted bit pattern using a public key of said point-of-sale terminal; and

electronically transferring said at least one re-encrypted bit pattern from said electronic wallet to said point-of-sale terminal.

8. The method of claim 7, wherein said step of storing further comprises the steps of:

encrypting said bit patterns using a secret key of a guaranteeing institution; and

encrypting said bit patterns using a public key of said electronic wallet to generate said doubly encrypted bit patterns.

9. The method of claim 7, wherein said step of decrypting further comprises the step of:

decrypting said at least one of said doubly encrypted bit patterns using a secret key of said electronic wallet.

10. The method of claim 7, wherein said electronic wallet is a smart card.

11. The method of claim 7, wherein said electronic wallet is a mobile phone.

12. The method of claim 7, further comprising the step of:

transmitting, from said point-of-sale terminal to said electronic wallet, said public key of said point-of-sale terminal.

13. The method of claim 7, further comprising the step of:

retrieving, from a memory device within said electronic wallet, said public key of said point-of-sale terminal.

14. A method for registering a bit pattern representative of an asset comprising the steps of:

generating a description of said asset;

encrypting said description using an institution'"'"'s secret key to create a single encrypted description;

encrypting said single encrypted description using an owner of said asset'"'"'s public key to create said bit pattern;

transmitting said bit pattern to a registry;

decrypting said bit pattern using said institution'"'"'s public key to yield said single encrypted description; and

authenticating said single encrypted description.

15. The method of claim 14, wherein said step of authenticating further comprises the step of:

performing a cyclic redundancy check on said single encrypted description after said decrypting step.

16. The method of claim 14, wherein said step of transmitting further comprises the step of:

transmitting an identity of said institution along with said bit pattern.

17. The method of claim 16, wherein said step of decrypting further comprises the step of:

retrieving, at said registry, said institution'"'"'s public key using said transmitted identity.

28. The method of claim 14, further comprising the steps of:

generating a cyclic redundancy check code using said description;

including said cyclic redundancy check code as part of said bit pattern transmitted to said registry.

29. The method of claim 28, wherein said step of generating a cyclic redundancy check code further comprises the step of:

using a nonlinear code computation to generate said cyclic redundancy check code.

34. The method of claim 14, wherein said registry is located in a telecommunication switch.

18. A method for trading electronic representations of assets comprising the steps of:

withdrawing, by a first party, from a first registry a first electronic representation of a first asset;

marking, by said first registry, said first electronic representation of said first asset as unavailable;

decrypting, by said first party, said first electronic representation of said first asset using said first party'"'"'s secret key;

re-encrypting, by said first party, said first electronic representation of said first asset using a second party'"'"'s public key; and

transmitting said first electronic representation of said first asset to said second party.

19. The method of claim 18, further comprising the steps of:

decrypting, by said second party, said first electronic representation of said first asset using said second party'"'"'s secret key;

decrypting, by said second party, said first electronic representation of said first asset using a first guaranteeing institution'"'"'s public key; and

reviewing a description of said first electronic representation of said first asset.

20. The method of claim 19, further comprising the steps of:

withdrawing, by said second party, from a second registry a second electronic representation of a second asset;

marking, by said second registry, said second electronic representation of said second asset as unavailable;

decrypting, by said second party, said second electronic representation of said second asset using said second party'"'"'s secret key;

re-encrypting, by said second party, said second electronic representation of said second asset using said first party'"'"'s public key; and

transmitting said second electronic representation of said second asset to said first party.

21. The method of claim 20, further comprising the steps of:

decrypting, by said first party, said second electronic representation of said second asset using said first party'"'"'s secret key;

decrypting, by said first party, said second electronic representation of said second asset using a second guaranteeing institution'"'"'s public key; and

reviewing a description of said second electronic representation of said second asset.

22. The method of claim 21, further comprising the steps of:

transmitting, by said first party to one of said first and second registries, said withdrawn version of said first electronic representation of said first asset, said first electronic representation of said first asset re-encrypted with said second party'"'"'s public key and a bit pattern expected in exchange from said second party; and

transmitting, by said second party to a same one of said first and second registries, said withdrawn version of said second electronic representation of said second asset, said second electronic representation of said second asset re-encrypted with said first party'"'"'s public key and a bit pattern expected in exchange from said first party.

23. The method of claim 22, further comprising the steps of:

comparing said bit pattern expected in exchange from said second party with said withdrawn version of said second electronic representation of said second asset;

comparing said bit pattern expected in exchange from said first party with said withdrawn version of said first electronic representation of said first asset; and

trading if both of said comparing steps result in a match by deleting said marked first and second electronic representations of said first and second assets in said first and second registries, respectively, and replacing same with said first electronic representation of said first asset re-encrypted with said second party'"'"'s public key and said second electronic representation of said second asset, said second electronic representation of said second asset re-encrypted with said first party'"'"'s public key, respectively.

24. The method of claim 23, further comprising the step of:

performing a cyclic redundancy check on said first electronic representation of said first asset.

25. The method of claim 23, further comprising the step of:

performing a cyclic redundancy check on said second electronic representation of said second asset.

26. The method of claim 18, wherein said first and second registries comprise a same database.

27. The method of claim 21, wherein said first and second guaranteeing institution are a same guaranteeing institution.

30. A method of providing secure electronic trades between a first party agreeing to trade a first asset and a second party agreeing to trade a second asset in return for said first asset comprising the steps of:

communicating, by said first party, with a first financial institution to obtain a first bit pattern describing said first asset, said first bit pattern being encrypted using a first cipher key known only to said first institution and further encrypted using a second cipher key supplied by said first party;

communicating, by said second party, with a second financial institution to obtain a second bit pattern describing said second asset, said second bit pattern being encrypted using a third cipher key known only to said second institution and further encrypted using a fourth cipher key supplied by said second party;

deciphering, by said first party, said first bit pattern using a cipher key inverse of said second cipher key known only to said first party and re-encrypting said first bit pattern using said fourth cipher key;

deciphering, by said second party, said first bit pattern using a cipher key inverse of said fourth cipher key known only to said second party and re-encrypting said second bit pattern using said second cipher key; and

exchanging, by electronic transmission between said first and second parties, said re-encrypted first and second bit patterns.

31. The method of claim 30 in which said first and second financial institutions are the same financial institution.

32. The method of claim 30 in which said first and third cipher keys are the same and their respective inverse keys are also the same.

33. The method of claim 30 in which at least one of said cipher keys comprises a first and second number, the first number being a product of ‘

n’

large primes P1,P2 . . . P(n) and the second number being a factor of the value 1+(P1-1)(P2-1) . . . (P(n)−

1), where ‘

n’

is equal to at least two.

35. An apparatus comprising:

a memory device for storing doubly encrypted bit patterns associated with monetary denominations; and

a device for deciphering a first doubly encrypted bit pattern associated with a first monetary denomination using a deciphering key to produce a once deciphered bit pattern, immediately re-encyphering said once deciphered bit pattern using a ciphering key to produce a second doubly encrypted bit pattern, and transmitting said second doubly encrypted bit pattern,

wherein said second doubly encrypted bit pattern is associated with the first monetary denomination, and

wherein the device removes from memory the once deciphered bit pattern after said re-encyphering and said transmitting.