BRITISH HMG INFOSEC STANDARD 5
The British HMG Infosec Standard 5 works as follows:
Pass 1: Overwriting the data with a zero;
Pass 2: Overwriting the data with a one;
Pass 3: Overwriting the data with a random character as well as verifying the writing of this character.
The British HMG Infosec Standard 5 is used by some data destruction programs. It serves to overwrite existing information on a hard disk or another storage medium. It is a software-based data erasure method. The HMG Infosec Standard 5 is almost identical to the DoD 5220.22-M procedure of the US Department of Defense.
If a hard disk is erased using the HMG Infosec Standard 5 data erasure method, a software-based restoration of the data is usually impossible. Also a hardware-based restoration of the data is in most cases excluded. The HMG Infosec Standard 5 method was originally described as HMG Information Assurance Standard No. 5 by the Communications Electronics Security Group (CESG), which is owned by the UK Government.