Problem:
Need to design a program that can encrypt and decrypt messages stored in simple text files using a private key stored in a separate file. Software should also be able to allow the users to enter simple messages that either displays the encrypted or decrypted message. The encryption method should use a simple substitution method. It should be set out in the following format:
Example (the "@" is the separator):
@
The character The Code End of line
A @ 4gh EOL
B @ 84!9 EOL
Has to use the 256 ASCII character codes. The separator will be used to separate the character and its corresponding code.
Here are the pseudocodes I have come up with:
• Read any private key file
separator = readline(file);
while not EOF(file) do
tempStr = readline(file);
tempArr = split(separator, tempStr);
matchArr += tempArr[0];
substitutionArr += tempArr[1];
endwhile;
• Allow users to enter messages (by entering text or file)
string1 = user input from textbox
• Encrypt and decrypt messages
Encrypting:
string1: get input from other module;
length: length of string1;
While Counter < length do;
string2 += substitute from subarray(character(counter) of string1)
endwhille;
Decrypting:
string1 = get input from other module;
Length = length of string1;
while counter < length do;
string2 += substitute from matcharray(character(counter) of string1)
endwhile;
• Display encrypted/decrypted message
textbox = string1
• Print encrypted/decrypted message
print encrypt (string1);
print decrypt (string1);
Can anyone point out if anything wont work/any fixes.
Cheers
-Ashur