ibps-so 2016 · Question 26 of 394

The information-security policy of Chandrabhaga Urban Bank distinguishes two treatments for storage that has held customer data at the end of its life. Under the rst, the data is overwritten so that it cannot be recovered, but the disk itself is t to be returned to the pool and issued again to another application. Under the second, applied to media that has held the most sensitive data of all, the disk is shredded, incinerated or otherwise reduced so that nothing can ever be read from it and the medium can never be used again by anybody. The audit committee has asked for the distinction between the two to be stated exactly. The distinction between erasure and destruction is correctly stated as follows:

1. AErasure removes the data only from the index and leaves the blocks themselves untouched, whereas destruction removes the index as well as the blocks but leaves the medium reusable
2. BErasure applies only to magnetic media and destruction only to optical media, the two being alternatives for di erent technologies rather than treatments of di erent severity
3. CErasure is performed by the database management system upon a table and destruction by the operating system upon a le, both leaving the medium una ected
4. DErasure destroys the medium and destruction merely overwrites the data, the names being drawn from the e ect upon the data rather than upon the medium
5. EErasure removes the data from the medium by overwriting or degaussing and leaves the medium t for reuse, whereas destruction renders the medium itself physically unusable so that neither the data nor the medium survivesCorrect