Falsification checking method of data sent by data recording apparatus having processor and a/d converter and data recording apparatus for executing the same

A method for executing a falsification check of data transmitted from a data recording device including a processor and an A/D converter. The method includes Step Sa0 of preparing a public-secret key pair; Step Sa1 of inputting an analog signal obtained by a sensor into the A/D converter, while the A/D converter generates whole digital data consisting of signal data and noise data; Step Sa2 of computing a hash value for the signal data using a hash function; Step Sa3 of encrypting the hash value with either of the secret key or the public key; Step Sa4 of writing the encrypted hash value into a noise area where the noise data is recorded, Step Sb2 of authenticating the received data; and Step Sb4 of determining whether the data transmitted from the data recording device is falsified.