I took up cryptography recently, and 1 of my task was to create a kama sutra cipher. Up till the point of generating the keys, I will have no problems. However, due to the nature of kama sutra, I believe that the keys are not supposed to be hard coded into the program, but rather generated for each plain text it takes in.
What I understand is that the cipher text’s length should be the same as the length of plain text. However, the thing is that where do I place the key, such that as long as the cipher text is generated by my program, the program would be able to decipher it even if the program was closed. Given that this is an algorithm, I am sure that I should not be looking at storing the key in another flat file/ database.
There are not many related information online regarding this cipher. What I saw are those that allow you to randomise a key set, generate a cipher text based on the given key set. When decrypting, you will also need to provide the same key set. Is this the correct way of implementation?
For those who have knowledge about this, please guide me along.
If you want to be able to decrypt the cyphertext, then you need to be able to recover the key whenever you need. For a classical cypher, this was usually done by using the same key for multiple messages, see the Caesar Cypher for an example. Caesar used a constant key, a -3/+3 shift while Augustus used a +1/-1 shift.
You may want to consult your instructor as to whether a fixed key or a varying key is required.
It will be simpler to develop a fixed key version, and then to add varying key functionality on top. That way you can get the rest of the program working correctly.
You may also want to look at classical techniques for using a keyphrase to mix an alphabet.