| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a data communication device which can detect data from being altered without receiving all divided data although a conventional data communication device is unable to detect the alteration of data until all divided data are received. SOLUTION: A CPU 1 divides data, computes digest values corresponding to the divided data, and ciphers and sends the digest values through a network additionally to the corresponding divided data, and a reception side authenticates a digest value corresponding to divided data received by a CPU 1 and outputs an alarm signal if the digest value is not authenticated.</p> |
