1. A method for preventing activation of hardware backdoors installed in a digital circuit, the digital circuit comprising at least one hardware unit to be protected, the method comprising: receiving by at least one obfuscation unit data intended to the at least one hardware unit; obfuscating the received data by the at least one obfuscation unit and outputting the data to the at least one hardware unit; processing the obfuscated data in the at least one hardware unit and outputting the processed obfuscated data; and de-obfuscating the processed obfuscated data in at least one de-obfuscation unit after the processed obfuscated data is output by the at least one hardware unit; wherein obfuscation of the data renders an activation code, embedded in the data, unrecognizable to a hardware backdoor when the hardware backdoor is present in the at least one hardware unit.