DATA TRANSMISSION METHOD, APPARATUS, AND SYSTEM

Embodiments of the present application disclose a data transmission method, apparatus, and system. The method includes: receiving, by an intermediate device, a first data transmission message sent by a first device and carrying first data, where the first data is target data encrypted by using a first encryption key; performing, by the intermediate device based on a first decryption key agreed upon between the intermediate device and the first device, decryption processing on the first data to obtain the target data, and performing preset data processing on the target data; performing, by the intermediate device based on a second encryption key agreed upon between the intermediate device and a second device, encryption processing on the target data that undergoes data processing, to obtain second data; and sending, by the intermediate device, a second data transmission message carrying the second data to the second device.