Patent ID: 11956359
Assignee: VISA INTERNATIONAL SERVICE ASSOCIATION
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 14:
15. A processing network computer comprising:
a processor; and
a non-transitory computer readable medium comprising instructions executable by the processor to perform operations including:
receiving, from a relying party computer associated with a relying party, a request for data associated with a user operating a user device, and a public encryption key associated with the relying party;
generating a second symmetric key;
encrypting the second symmetric key with the public encryption key associated with the relying party to form an encrypted second symmetric key;
encrypting first encrypted data associated with the user with a second keystream to form first doubly encrypted data, wherein the second keystream is generated using a keystream generation function with the second symmetric key and a second nonce as input, wherein the first encrypted data associated with the user comprises plaintext data associated with the user, and wherein the plaintext data associated with the user is encrypted with a first keystream that is generated using the keystream generation function with a first symmetric key and a first nonce as input;
transmitting, to the user device, an encrypted first symmetric key, the first nonce, the first doubly encrypted data, and the public encryption key associated with the relying party;
receiving, from the user device, an encrypted third symmetric key, a third nonce, and second doubly encrypted data, wherein the second doubly encrypted data was formed by encrypting second encrypted data associated with the user with a third keystream that is generated using the keystream generation function with a third symmetric key and the third nonce as input; and
transmitting, to the relying party computer, the encrypted second symmetric key, the encrypted third symmetric key, the second nonce, the third nonce, and the second doubly encrypted data, wherein after the relying party computer receives the encrypted second symmetric key, the encrypted third symmetric key, the second nonce, the third nonce, and the second doubly encrypted data from the processing network computer, the relying party computer:
decrypts the encrypted second symmetric key and the encrypted third symmetric key to obtain the second symmetric key and the third symmetric key; and

decrypts the second doubly encrypted data using the second symmetric key, the second nonce, the third symmetric key, and the third nonce to obtain the plaintext data associated with the user.