File C:

'HBNDERKERMFTSRZOVLKVEMDQRHRZFSOKARERHKVUKARHRXRSKMRPRSAFQDSXFHJROPRKVTEDKROVTSKARTAVMRYFEKDLNMFEHFIVNKKERFHNERDHMFSOUEVPKARIRXDSSDSXKVKARRSOJRRYDSXSVKADSXIFLJINKKARIRFEDSXHVUKARDHMFSOFSOKAFKVSMZIRLFNHRKARERDHHKDMMKERFHNERSVKZRKMDUKRODKFJRNYPZYRSDSKARZRFEVUXEFLRFSOXVIFLJKVKARKDPRTARSPZUFKAREJRYKKARFOPDEFMIRSIVTDSSFSOKARIEVTSVMOHRFPFSTDKAKARHFIRELNKUDEHKKVVJNYADHMVOXDSXNSOREVNEEVVU'

4. (9 marks) The following text has been encrypted using an affine cipher. HBNDERKERMFTSRZOVLKVEMDQRHRZFSOKARERHKVUKARHRXRSKMRPRSAFQDSXFHJROPRKVTEDKROVTSK ARTAVMRYFEKDLNMFEHFIVNKKERFHNERDHMFSOUEVPKARIRXDSSDSXKVKARRSOJRRYDSXSVKADSXIFLJ INKKARIRFEDSXHVUKARDHMFSOFSOKAFKVSMZIRLFNHRKARERDHHKDMMKERFHNERSVKZRKMDUKRODKF J RNYPZYRSDSKARZRFEVUXEFLRFSOXVIFLJKVKARKDPRTARSPZUFKAREJRYKKARFOPDEFMIRSIVTDSSFS OK AR? EVTSVMOHRFPFSTDKAKARHFI RELNKUDEHKKVV JNYADHMVOXDSXNSOREVNEEVV? (You don't need to type this in - download the file C.mat from canvas and load that into matlalb using the command load('C a) Convert the resulting cypher text variable C to a vector cn of integers using chartoint. Plot a histogram of the integers in cn using the Matlab command hist (cn, 0:25) b) Use your histogram to identify the most frequent character and the second most frequent character in the cypher text c) The most frequent character in English is-E and the second most frequent is .T". se this information to help you decypher the affine cypher text