hill cipher example...

ow that i've spent over a week trying to figure out
this thing , i just want 2 share it with u all


finding the decryption matrix in case of hill cipher encryption algo
will be quite a joy ride once u see the following link

BTW me nd rupli had already discovered the mod table for 26 and
finalized what we were supposed to do but this link was icing on
the cake..
only if it could have been discovered some dayz back it
would have let us avoid spending around 3hrs on msgr (over a period of
2 dayz )
and that does'nt include time spent individually ..........



so w/o much delay u can refer this link::
http://www.runcornshs.eq.edu.au/staff/balshaw/partb.htm

this will make things clearer


just remember we're finding multiplicative inverse modulo and
not simple modulus

and they are in pairs

(3 * 9) =(1 mod 26)

so (1/3)mod26 will give us 9

and (1/9)mod26 will give us 3








and for those who dont have time to waste on that link

for the ques given in asg...

inverse of ( 9 4.......is......(5 12
................5 7) ..............15 25)


here we used (1/43)mod26= (1/43mod26)mod26

=(1/17)mod26

=23




ps.. this will make sense only to those who have already
have some idea bout what im talking about



tc...