Proximity-based tokenized data transmission for interoperable device platforms

A first user device associated with a first account identifier, the first user device comprising:

• a processor;
• and
• a non-transitory computer-readable medium storing instructions that, when executed by the processor, cause the first user device to perform operations comprising:
• determining that a second user device is within a threshold distance of the first user device and, in response, receiving a second account identifier from the second user device, wherein the first account identifier and the second account identifier are associated with respective accounts hosted by a service;
• and
• in response to receiving the second account identifier from the second user device:
• generating a cryptographically signed message to the second user device based on a session key and user input on the first user device, wherein the session key is received from the service and is generated based on the user input;
• transmitting, to the second user device, the cryptographically signed message, wherein the cryptographically signed message is configured to allow secure communication of information from the first user device to the second user device;
• and
• receiving, from the service, an indication that an account associated with the first account identifier has been modified in accordance with the user input.

A non-transitory computer-readable medium storing instructions that, when executed by a processor of a first user device, cause the first user device to perform operations comprising:

• detecting a second user device within a threshold distance from the first user device and, in response:
• requesting a session key from a remote service, the session key including a cryptographic key configured to allow secure transmission of information from the first user device to the second user device;
• receiving the session key, wherein the session key is generated based on a set of message contents;
• generating a cryptographic signature based on the set of message contents, wherein the cryptographic signature includes a cryptographic representation of the set of message contents to allow secure verification of the set of message contents by the remote service;
• transmitting, to the second user device, a message including the set of message contents and the cryptographic signature;
• and
• receiving an indication that an account has been modified in accordance with the set of message contents, wherein the account associated with the remote service and the first user device.