Data deletion and data erasure
may sound similar, as one may consider both the actions as ways to “remove
In layman terms, you may think
of “data deletion” as emptying a file from the Recycle Bin or Trash (in Mac) or
using SHIFT+DEL command to remove a
file from a visible location on your system or external drive to an unknown
location. Likewise, “data erasure” can be erasing
(or wiping) the data so that it vanishes from the storage media to somewhere
unknown like a piece of information is erased from paper.
fact is, both data deletion and data erasure are fundamentally different in
every sense; from their purpose and mechanism to the end-results.
This blog brings out the
difference in data deletion & data erasure by outlining the critical
differences between them. More importantly, it explains why you should be
concerned about knowing this difference in today’s world of data
vulnerabilities and data protection laws.
Let us begin with understanding what happens when you DELETE data vis-à-vis when you ERASE it.
- Data Deletion
Technically, the operating
system uses a ‘file system’, i.e. a table structure, to keep track of all the
logical storage units or clusters on the hard disk and how these clusters store
and retrieve data. You may have heard of the File Allocation Table (FAT) &
New Technology File System (NTFS) drives in Windows or Apple File System (APFS)
volume in macOS. These are some types of file systems used for storing and
retrieving the data, i.e. which file is stored from cluster 1 to cluster ‘n’,
and so forth. The file allocation table stores the addresses, also known as
pointers, of the data stored on the clusters (or Nodes in Mac system).
When a file is deleted, the
operating system deletes the pointers to the file and marks the corresponding
cluster in FAT or master file table (MFT) as ‘available’ for storing new file
You may be surprised to know
that ‘deletion’ does not necessarily delete the file or actual data, but only
the pointer, i.e. address to the file, due to which the file becomes invisible
and inaccessible to normal usage by user. However, be informed that the deleted
file – even the one emptied from the Recycle Bin or deleted using Shift + Del
command –still resides in the storage media. It can be retrieved easily using a
simple DIY Data Recovery software like Stellar
- Data Erasure
Data erasure, on the other
hand, involves overwriting the existing data on a storage sector with binary
patterns like ‘1s’ and ‘0s’ or meaningless pseudo-random patterns with the
purpose to destroy or sanitize it.
‘Data erasure’ also called as
data destruction in general aims to eradicate or sanitize the data to render it
completely unusable. In simple words, the data turns illegible after it is
erased or overwritten with binary patterns.
The overwriting methods used
for performing data erasure on a storage media differ in terms of the patterns
and passes used (i.e. the number of times a pattern is written) and also how
the outcome of a given overwriting method on a drive is verified. For example,
5220.22-M method uses three passes of 0s, 1s, and random character
for data erasure with a 100% verification.
Data Deletion vs Data Erasure: A Quick Comparison
The following table presents a
comparison between deletion and erasure across several key aspects:
of the data is deleted from the master file table (MFT), and the space is
marked as available in the MFT.
overwritten with specific binary patterns, resulting in the sanitization of
storage media beyond data recovery.
by using Shift + Del command in Windows or Option + Command + Delete in
the data can be manually emptied from the Recycle Bin or Trash for permanent
a software tool is used for data erasure like BitRaser, which
implements the overwriting pattern based on the standard used, such as US DoD
5220.22, NIST 800-88, British – HMG, etc. Software erases data and provides a
certificate of erasure.
of empty storage space for fresh usage. However, deleted data is present in
the system in a readable form by any DIY software.
data is overwritten, and the drive is available for reuse without any traces
of data left behind.
data can be recovered using a DIY data recovery tool or manual/lab
data is no longer present on the system & cannot be retrieved by any
means – software or in-lab methods/techniques.
Data Deletion: A Note on Public Awareness
Despite deletion being a
common action every computer user does with everyday system usage, it is
surprising to find that not as many users are aware of what happens with file
And that is what a lab
investigation had revealed in 2019. The study had investigated 311
used devices, including hard disks, SD cards, and mobile phones, to find that 1
in every 4 devices or 25% devices were disposed of after either deleting the
files or formatting the media. The users had used deletion and formatting as the
actions for data removal and had,
therefore put their sensitive data at risk of potential leakage. They were not
aware of data erasure as the process meant for destroying sensitive
Dangers of Data Deletion
As understood earlier, data
deletion is the process of creating fresh storage space, and it has nothing to
do with the removal of data from the standpoint of protecting users’ data
privacy. So, being ignorant of this fact can put your data at risk of leakage
The study referenced earlier
in this blog had also revealed a surprising variety of sensitive personal and
business data found present on the disposed of devices. This data was comprised
of personal photos and videos, passport and visa details, driving license,
national identity card, income tax records, invoices, banking information, etc.
of this data to an unauthorized third party could lead to grave outcomes like
identity theft, financial fraud, personal security threat, brand damage, IP
theft, customer loss, and even litigation. For organizations, data deletion can
lead to data breach episodes and non-compliance with laws and regulations and
incur huge penalties.
Adopt Secure Data Erasure to Get Rid of Unwanted Data
erasure provides one of the safest and most efficient ways to eradicate
redundant data. As understood earlier, the process is based on overwriting the
addressable memory locations with binary patterns to destroy the data,
rendering it unrecoverable using any data recovery tool or technique.
BitRaser Drive Eraser is a
professional software, which implements data erasure as per 24 global standards
such as NIST 800-88, US-DoD 5220.22-M, Peter Gutmann, etc. The tool securely erases
the complete storage media, including the hidden area of the storage media
& remapped sectors.