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Tech
Funda
For iris and retinal recognition, it is advisable to remove eye glasses and
contact lenses.
(iii) Voice Recognition: The term voice recognition refers to finding the identity of a person
who is speaking, rather than what he/she is saying. Recognising the speaker can simplify
the task of translating speech into system that has been trained on a specific person’s
voice or it can be used to authenticate or verify the identity of a speaker as part of a
security process.
Encryption: Encryption is the process of conversion of data and information into a
form, called ciphertext, that cannot be easily understood by unauthorised people.
Decryption: It is the process of converting encrypted data back into its original form,
so that it can be understood.
The use of encryption/decryption is as old as the art of communication. In older day, at
the time of war, a cipher, often called as code, was employed to keep the enemy away
from obtaining the contents of transmissions.
Simple ciphers include the substitution of letters for numbers, the rotation of letters
in the alphabet, and the ‘scrambling’ of voice signals by inverting the sideband
frequencies. Some complex ciphers work according to sophisticated computer
algorithms that rearrange the data bits in digital signals. For example, take a look at
the following code:
Jogpsnbujpo Qspufdujpo
Do you understand the code or does it make any sense? No. This is because it is
written in encripted form. However, if you know the decipher, you can decipher it.
Try replacing every letter in the message with the letter preceding it in the alphabet.
You will find that the code is:
Information Protection
HOW TO BACKUP YOUR IMPORTANT FILES?
Now you will learn how to back up your computer files. It is another important step for computer
safety. Have you lost any important documents, photos or other files? Imagine what would
happen if your computer suddenly stopped working.
It may be possible to repair your computer, but your files may be lost forever. Luckily, you
can prevent this by creating backup copies of all of your files (or just the important ones) on
an external hard disk drive or an online backup service.
External Hard Disk Drives
To keep your file safe, you can purchase an external hard disk drive
and copy the content of your computer on it. The initial backup could
take several hours. Follow-up backup should be conducted on a
regular basis, but it may not take long because the drive will only need External Hard Disk Drive
to copy your most recent files.
Computer Safety and Security 91

