System and method for information protection

1. A non-transitory computer-readable storage medium of a sender node associated with a sender of a transaction, the storage medium storing instructions that, when executed by a processor, cause the processor to perform operations comprising:

generating a transaction commitment value T by committing a transaction amount t of the transaction according to a commitment scheme based at least on a transaction blinding factor r_t;

sending the transaction amount t, the transaction blinding factor r_t, and the transaction commitment value T to a recipient node associated with a recipient of the transaction for the recipient to verify the transaction and to encrypt the transaction blinding factor r_t and the transaction amount t with a public key PK_B of the recipient;

obtaining an encrypted combination of the transaction blinding factor r_t and the transaction amount t from the recipient node after the recipient successfully verifying the transaction; and

transmitting an updated version of the transaction to a plurality of nodes in a blockchain for the plurality of nodes to verify the transaction, the updated version of the transaction comprising the encrypted combination and the transaction commitment value T.

2. The storage medium of claim 1 , wherein the commitment scheme comprises a Pedersen commitment with the transaction amount t being a committed value.

3. The storage medium of claim 1 , wherein the encrypted combination of the transaction blinding factor r_t and the transaction amount t comprises an encrypted concatenation of the transaction blinding factor r_t and the transaction amount t.

4. The storage medium of claim 1 , wherein before transmitting the encrypted combination and the transaction commitment value T to the plurality of nodes, the operations further comprise:

generating a change commitment value Y by committing a change y of the transaction with the commitment scheme based at least on a change blinding factor r_y, wherein the change y is one or more assets of the sender that are tapped for the transaction less the transaction amount t; and

encrypting a combination of the change blinding factor r_y and the change y with a public key PK_A of the sender.

5. The storage medium of claim 1 , wherein before transmitting the encrypted combination and the transaction commitment value T to the plurality of nodes, the operations further comprise:

obtaining from the recipient node a recipient signature SIGB generated by the recipient signing the transaction with a private key SK_B of the recipient, wherein the recipient signature SIGB represents that the recipient has approved the transaction.

6. The storage medium of claim 5 , wherein before transmitting the encrypted combination and the transaction commitment value T to the plurality of nodes, the operations further comprise:

in response to receiving the recipient signature SIGB, generating a sender signature SIGA by signing the transaction with a private key SK_A of the sender, wherein the recipient signature SIGA represents that the sender has approved the transaction.

7. The storage medium of claim 6 , wherein before transmitting the encrypted combination and the transaction commitment value T to the plurality of nodes, the operations further comprise:

generating the updated version of the transaction, the updated version of the transaction comprising the encrypted combination, the transaction commitment value T, the sender signature SIGA, and the recipient signature SIGB.

8. A computer-implemented method for information protection, performed by a sender node associated with a sender of a transaction, comprising:

generating a transaction commitment value T by committing a transaction amount t of the transaction according to a commitment scheme based at least on a transaction blinding factor r_t;

sending the transaction amount t, the transaction blinding factor r_t, and the transaction commitment value T to a recipient node associated with a recipient of the transaction for the recipient to verify the transaction and to encrypt the transaction blinding factor r_t and the transaction amount t with a public key PK_B of the recipient;

obtaining an encrypted combination of the transaction blinding factor r_t and the transaction amount t from the recipient node after the recipient successfully verifying the transaction; and

transmitting an updated version of the transaction to a plurality of nodes in a blockchain for the plurality of nodes to verify the transaction, the updated version of the transaction comprising the encrypted combination and the transaction commitment value T.

9. The method of claim 8 , wherein the commitment scheme comprises a Pedersen commitment with the transaction amount t being a committed value.

10. The method of claim 8 , wherein the encrypted combination of the transaction blinding factor r_t and the transaction amount t comprises an encrypted concatenation of the transaction blinding factor r_t and the transaction amount t.

11. The method of claim 8 , before transmitting the encrypted combination and the transaction commitment value T to the plurality of nodes, further comprising:

generating a change commitment value Y by committing a change y of the transaction with the commitment scheme based at least on a change blinding factor r_y, wherein the change y is one or more assets of the sender that are tapped for the transaction less the transaction amount t; and

encrypting a combination of the change blinding factor r_y and the change y with a public key PK_A of the sender.

12. The method of claim 8 , before transmitting the encrypted combination and the transaction commitment value T to the plurality of nodes, further comprising:

obtaining from the recipient node a recipient signature SIGB generated by the recipient signing the transaction with a private key SK_B of the recipient, wherein the recipient signature SIGB represents that the recipient has approved the transaction.

13. The method of claim 12 , before transmitting the encrypted combination and the transaction commitment value T to the plurality of nodes, further comprising:

in response to receiving the recipient signature SIGB, generating a sender signature SIGA by signing the transaction with a private key SK_A of the sender, wherein the recipient signature SIGA represents that the sender has approved the transaction.

14. The method of claim 13 , before transmitting the encrypted combination and the transaction commitment value T to the plurality of nodes, further comprising:

generating the updated version of the transaction, the updated version of the transaction comprising the encrypted combination, the transaction commitment value T, the sender signature SIGA, and the recipient signature SIGB.

15. A system of a sender node associated with a sender of a transaction, the system comprising a non-transitory computer-readable storage medium storing instructions that, when executed by a processor, cause the processor to perform operations comprising:

generating a transaction commitment value T by committing a transaction amount t of the transaction according to a commitment scheme based at least on a transaction blinding factor r_t;

sending the transaction amount t, the transaction blinding factor r_t, and the transaction commitment value T to a recipient node associated with a recipient of the transaction for the recipient to verify the transaction and to encrypt the transaction blinding factor r_t and the transaction amount t with a public key PK_B of the recipient;

obtaining an encrypted combination of the transaction blinding factor r_t and the transaction amount t from the recipient node after the recipient successfully verifying the transaction; and

transmitting an updated version of the transaction to a plurality of nodes in a blockchain for the plurality of nodes to verify the transaction, the updated version of the transaction comprising the encrypted combination and the transaction commitment value T.

16. The system of claim 15 , wherein the encrypted combination of the transaction blinding factor r_t and the transaction amount t comprises an encrypted concatenation of the transaction blinding factor r_t and the transaction amount t.

17. The system of claim 15 , wherein before transmitting the encrypted combination and the transaction commitment value T to the plurality of nodes, the operations further comprise:

generating a change commitment value Y by committing a change y of the transaction with the commitment scheme based at least on a change blinding factor r_y, wherein the change y is one or more assets of the sender that are tapped for the transaction less the transaction amount t; and

encrypting a combination of the change blinding factor r_y and the change y with a public key PK_A of the sender.

18. The system of claim 15 , wherein before transmitting the encrypted combination and the transaction commitment value T to the plurality of nodes, the operations further comprise:

obtaining from the recipient node a recipient signature SIGB generated by the recipient signing the transaction with a private key SK_B of the recipient, wherein the recipient signature SIGB represents that the recipient has approved the transaction.

19. The system of claim 18 , wherein before transmitting the encrypted combination and the transaction commitment value T to the plurality of nodes, the operations further comprise:

in response to receiving the recipient signature SIGB, generating a sender signature SIGA by signing the transaction with a private key SK_A of the sender, wherein the recipient signature SIGA represents that the sender has approved the transaction.

20. The system of claim 19 , wherein before transmitting the encrypted combination and the transaction commitment value T to the plurality of nodes, the operations further comprise:

generating the updated version of the transaction, the updated version of the transaction comprising the encrypted combination, the transaction commitment value T, the sender signature SIGA, and the recipient signature SIGB.