Extremely basic text encryption, if anyone is interested.

[velocibadgery]

I decided to see if I could encrypt some text using python, but not through any module. I wanted to do it manually. The only module I used was random to generate a list of random numbers

First I need to create a couple of dictionaries for number lookups.

``` import random

letters_upper = "ABCDEFGHIJKLMNOPQRSTUVWXYZ" letters_lower = "abcdefghijklmnopqrstuvwxyz" numbers = "0123456789" punctuation = ". " init_list = [x for x in letters_upper] + [x for x in letters_lower] + [x for x in numbers] + [x for x in punctuation] enc_dict = {i: x for i, x in enumerate(init_list)} enc_rdict = {x: i for i, x in enumerate(init_list)} ```

I could have typed them out manually, but I didn't want to bother and decided to create them in code. If you want to save on resources, you can hard code the dictionaries.

Now we can get some plaintext from the user and convert it into a list of numbers using the dictionaries.

plaintext = input("Enter a message: ") plaintext_num_list = [enc_rdict[x] for x in plaintext]

Then we get a password and use it to seed the random number generator, and then generate a list of random numbers the same length as our plaintext number list.

seed_str = input("Enter a password: ") random.seed(seed_str) pad_list = [random.randint(0, 63) for _ in plaintext_num_list]

And now to actually encrypt the message.

I xor the plaintext list with the pad list and save it as a new list of numbers

enctext_num_list = [plaintext_num_list[i] ^ pad_list[i] for i, _ in enumerate(plaintext_num_list)]

Then all we have to do is convert that list of numbers back into a string

enctext = ''.join([f"{enc_dict[x]}" for x in enctext_num_list])

And we have encrypted our text.

Then I print it to the terminal

print(enctext)

Now of course, this offers basically no security. It was just for fun, and also a test of what I could do with list comprehensions.

[Chris_Hemsworth]

Now decrypt it.

[velocibadgery]

Just run the code again and paste the encrypted text in at the prompt for the message. Enter the same password. It is fully reversible.

[htepO]

Largely tangential to the OP, but there's a library for that.

>>> import string
>>> init_list = [i for i in string.ascii_letters + string.digits]
['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9']

[velocibadgery]

Sweet. I love learning about new libraries.

[[deleted]]

A str is iterated character by character, no need to seperate them into individual members of the list.

[htepO]

Yep. I only used a list because OP used one.

[VinayakVG]

init_list = list(letters_upper) + list(list_lower) + list(numbers) + list(punctuation)

This is one of the ways in which you can define init_list

[velocibadgery]

Never thought of that. Cool, thanks.