Page 25 - Trackpad_V2.1_class8
P. 25

21 st
                                                                                            Century   #Media Literacy
                                                                                             Skills
                      Video based question                                                                 Scan the
                                                                                                           QR Code
                      Watch the video and answer the question.
                         Which wireless media exchanges data over a short distance








                                                                                           21 st
                      LAB ACTIVITY                                                      Century   #Technology Literacy
                                                                                          Skills
                       Visit your computer lab and perform the following actions:
                       ▶   Explore the Internet to learn about different networks and their functions.
                             a.   Create a presentation based on the information gathered, incorporating relevant pictures as
                              well.
                             b.   Present your presentation to your class.






                         COding Zone       COding Zone    {}      =      COding Zone               COding Zone
                                {C ding z ne}
                                                                                          21 st
                                                                                                            []
                                                                                              #Computational Thinking
                                                                                        Century
                                                                         </>
                                                                                          Skills
                    For transmitting  our data  over a network  in a safe  and  secure  manner, various  encryption
                    techniques  are used  to  convert our plain text  message  into  cipher text.  For  this  conversion,
                    different techniques are used. Some of them are explained below:
                    Substitution Technique

                    In this technique, we simply replace the letters in our message with other letters or symbols.

                    One of the simplest substitution techniques is the Caesar Cipher which was developed by Julius
                    Caesar. In this technique, each letter of the plain text is replaced by the letter three places ahead
                    of it. Therefore, to decrypt the cipher text, the letter of cipher text is replaced by letter three
                    places before it.

                    Example:

                       Plain text: Today is Sunday

                       Cipher text: wrgdb lv vxqgdb

                    We have simply replaced each letter of the plain text with the letter three places ahead of it.

                    Transposition Technique

                    In this technique, the identity of the letters remains the same but their positions are changed to
                    create the cipher text.







                                                                                              Networking Concepts  23
   20   21   22   23   24   25   26   27   28   29   30