Encrypting a message using secret key in python

Question

I need to encrypt a message using a secret key and return the message. I tried this and I got the correct output.

def my_encryption(some_string):
    character_set= "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 "
    secret_key="    Dd18Abz2EqNPW hYTOjBvtVlpXaH6msFUICg4o0KZwJeryQx3f9kSinRu5L7cGM"
    m=some_string
    k=m.translate({ord(x): y for (x, y) in zip(character_set,secret_key )})
    return m

print(my_encryption("Lets meet at the usual place at 9 am"))

The output I got is

oABjMWAABMDBMB2AMvjvDPMYPD1AMDBMGMDWB

and this is correct. I would like to know, will there be any other way to do this with out using translate?. I am curious to know the alternate ways. I will be glad to know. Thank you.

score 2 · Answer 1 · answered Feb 28 '16 at 22:19

you can use a simple dictionary

def my_encryption(some_string):
    character_set= "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 "
    secret_key=    "Dd18Abz2EqNPW hYTOjBvtVlpXaH6msFUICg4o0KZwJeryQx3f9kSinRu5L7cGM"
    table = {x: y for (x, y) in zip(character_set,secret_key )}
    return "".join( map(lambda x:table.get(x,x),some_string) )

the get method can receive 2 arguments, the first is the key to search and the second is a value to return in case that the key is not present, in this case assign that as x to leave that unchanged

here a test

>>> my_encryption("Lets meet at the usual place at 9 am")
'oABjMWAABMDBMB2AMvjvDPMYPD1AMDBMGMDW'
>>>

this is usually the first thing that come to my mind when I want to do this simple substitution cipher.

and the inverse is as simple as invert key-value

def my_decription(some_string):
    character_set= "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 "
    secret_key=    "Dd18Abz2EqNPW hYTOjBvtVlpXaH6msFUICg4o0KZwJeryQx3f9kSinRu5L7cGM"
    table = {x: y for (x, y) in zip(character_set,secret_key )}
    return "".join( map(lambda x:table.get(x,x),some_string) )

>>> my_decription('oABjMWAABMDBMB2AMvjvDPMYPD1AMDBMGMDW')
'Lets meet at the usual place at 9 am'
>>>

score 1 · Answer 2 · answered Feb 25 '16 at 15:18

1

A simple solution I use when making things less plain text is base64 module. This is not encryption by any means. Just makes the text a little harder to read:

>>> import base64
>>> base64.b64encode(b'This is a secret.')
b'VGhpcyBpcyBhIHNlY3JldC4='
>>> base64.b64decode(b'VGhpcyBpcyBhIHNlY3JldC4=').decode('utf-8')
'This is a secret.'

answered Feb 25 '16 at 15:18

Igor

1,212
12
23

1

no, if you observe the character set and secret key, a is mapped to D and b is mapped to d and so on.. with that character set only i would like to perform operations. i want to know the various ways other than usage of translate. – rocky25bee Feb 25 '16 at 15:48
1

it is encrypting using the secret key above not just encrypting randomly. – rocky25bee Feb 25 '16 at 15:57
Ah I see. Maybe this answer would be of some use? [Simple way to encode a string according to a password?](http://stackoverflow.com/questions/2490334/simple-way-to-encode-a-string-according-to-a-password) – Igor Feb 25 '16 at 18:01

Sameera Talari · Answer 3 · 2019-05-20T11:29:09.373

0

def my_encryption(some_string):
     output_string=""
     index=0
     character_set = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 "
     secret_key    = "Dd18Abz2EqNPW hYTOjBvtVlpXaH6msFUICg4o0KZwJeryQx3f9kSinRu5L7cGM"
     for character in some_string:
        index=character_set.find(character)
        output_string=output_string+secret_key[index]
      return output_string

edited May 20 '19 at 11:29

answered May 20 '19 at 11:27

Sameera Talari

1
1

3

While this code may solve the question, [including an explanation](https://meta.stackexchange.com/questions/114762/explaining-entirely-code-based-answers) really helps to improve the quality of your post. – 4b0 May 20 '19 at 11:29

Encrypting a message using secret key in python

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