# Need ur help and comments

(ahmed_seh) #1

## [B][LEFT]hello guys, how r u? i hope u r fine and ok… i wanna design project for encryption and decryption software package and i wanna use fliparound technique at transmitter there is no problem its ok but at receiver i couldnt get the data back as it was be4 sending it., lets take this example: at transmitter: e: stands for encryption process e=double(‘here i will explain the method here in this forum’) leng=length(e), %leng stands for length of message r=randint(1,3,[1 255]) e(1:end)=e(end:-1:1) %flip around elements in matrix e e1=randperm(leng) e=e(e1) %change position of elements in matrix e according to matrix e1 e2=[e r] %combine two matrices into one matrix e3=char(e2) % encrypted output result

at receiver: d stands for decryption process
d=double(e3)
r=d(end-2:end) %retrieve the 3 random numbers generated at transmitter
d(end-2:end)=[] % delete value of random numbers.
leng=length(d)
d1=randperm(leng)
d(d1)=d
d(1:end)=d(end:-1:1) %here i tried the get data back 2 its original positions but it seems there is something wrong or missing.
% could any one help me with that???
d2=char(d) % output here is not same as it was be4 sending.
guys u can try this code and tell me ur opinions about it and what are ur comments?? also do u think : is it easlly to be broken???
how can i make it more strong and difficult to be broken and decrypted by hacker
waiting 4 ur reply and response
[/left]
[/b]

(المهندس سعود) #2

the error in this code in thefollowing line

``````d1=randperm(leng)
``````

it must be the same as in transmitter
d1=e1

(المهندس سعود) #3

i think it is bad code
i will see you a nice code

but i found some problems

see you

(ahmed_seh) #4

thank u very much

waiting 4 ur reply guys and waiting 4 ur code eng soud