Enabling confidential and non-confidential transactions on a digital token architecture
Introduced here is a new program that was developed to provide privacy for data stored on a blockchain. This new program was designed to be deployed on the blockchain as an extension to the existing program that allows non-confidential transfers of funds. This new can work in conjunction with the existing program to permit users to conduct confidential and non-confidential transactions as necessary based on the sensitivity of the data involved.
1. A non-transitory medium with instructions stored thereon that, when executed by a processor of a computing device, cause the computing device to perform operations comprising:
receiving input indicative of an instruction from an owner to initialize an account for a first program that permits confidential transfers of tokens;
establishing, in response to said receiving, that the owner is associated with another account for a second program that permits non-confidential transfers of tokens; and
initializing, in response to said establishing, the account by populating a data structure with (i) an account address, (ii) a mint address, (iii) an owner address, and (iv) a balance that is encrypted using a public cryptographic key associated with the owner.
2. The non-transitory medium of claim 1 , wherein the operations further comprise:
permitting, in response to said initializing, the owner to participate in confidential transfers of tokens to and from the account.
3. The non-transitory medium of claim 2 , wherein the operations further comprise:
receiving second input indicative of a request to initiate a confidential transfer from the account initialized for the owner to a second account associated with a recipient;
subtracting a first ciphertext included in the second input from the encrypted balance of the account; and
adding a second ciphertext included in the second input to an encrypted balance of the second account.
4. The non-transitory medium of claim 3 , wherein the second input includes (i) the first ciphertext that is encrypted under the public cryptographic key associated with the owner, (ii) the second ciphertext that is encrypted under a public cryptographic key associated with the recipient, (iii) a range proof, and (iv) an equality proof.
5. The non-transitory medium of claim 1 , wherein the operations further comprise:
deriving the account address based on (i) an account address of the other account for the second program and (ii) a mint address of the other account for the second program.
6. The non-transitory medium of claim 1 , wherein the balance is encrypted using an encryption scheme that is linearly homomorphic.
7. The non-transitory medium of claim 6 , wherein the encryption scheme is the ElGamal encryption scheme.
8. A non-transitory medium with instructions stored thereon that, when executed by a processor of a computing device, cause the computing device to perform operations comprising:
receiving input indicative of a request to initiate a confidential transfer from a first account associated with a sender to a second account associated with a recipient,
wherein the input includes (i) a first ciphertext encrypted under a public cryptographic key of the sender, (ii) a second ciphertext encrypted under a public cryptographic key of the recipient, (iii) a range proof, and (iv) an equality proof;
subtracting the first ciphertext from an encrypted balance of the first account; and
adding the second ciphertext to an encrypted balance of the second account.
9. The non-transitory medium of claim 8 , wherein the equality proof certifies that the first and second ciphertexts encrypt a same value.
10. The non-transitory medium of claim 8 , wherein the operations further comprise:
storing a hash that is representative of the confidential transfer on a blockchain associated with a program that permits confidential transfers.
11. The non-transitory medium of claim 10 , wherein the first account is associated with another account for a second program that permits non-confidential transfers.
12. The non-transitory medium of claim 11 , wherein the second program is associated with a second blockchain on which hashes representative of non-confidential transfers are stored.
13. A non-transitory medium with instructions stored thereon that, when executed by a processor of a computing device, cause the computing device to perform operations comprising:
receiving input indicative of a request to initiate a confidential transfer from a first account associated with a sender to a second account associated with a recipient,
wherein the input includes (i) a first ciphertext encrypted under a public cryptographic key of the sender, (ii) a second ciphertext encrypted under a public cryptographic key of the recipient, (iii) a range proof, and (iv) an equality proof;
merging the first and second ciphertexts to create a merged ciphertext;
subtracting the merged ciphertext from an encrypted balance of the first account; and
adding the merged ciphertext to an encrypted balance of the second account.
14. The non-transitory medium of claim 13 , wherein said merging is performed in a homomorphic manner.
15. The non-transitory medium of claim 13 , wherein the first and second ciphertexts are 32-bit numbers, and wherein the merged ciphertext is a 64-bit number.