The invention discloses system and method for data authentication among processors. The method comprises: generating a first key, by a first processor, according to a first identification data and a first algorithm; generating a first digest, by the first processor, according to data to be transmitted, the first identification data and a second algorithm; generating a digital signature, by the first processor, according to the first key, the first digest and a third algorithm; and transmitting the data and the digital signature from the first processor to a second processor.