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(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 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

                     TAKING BACKUP OF 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
                 to copy your most recent files.                                             External Hard Disk Drive






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