Hello, this is my first post on DaniWeb so I hope you'll go easy on me ,and my english.I'm working on a implementation of the AES algorithm in python;my app is supposed to encrypt the contents of files, and it does, yet it is kind of slow.I've optimized the code as good as I could because I am a beginner , but I would like to know if there is a way to reduce the amount of text , before I go through the encryption phase with it.I cannot use PyCrypto, nor OOP ( well I can only use OOP for the interface, silly requirements..), I used Galois multiplication tables for the MixColumns operation to further reduce the execution time, so if you have some ideea of how I could reduce the amount of text , please do tell.
Thank you for your help.

Perhaps you could compress the text first to reduce its size

import zlib
text = open("file_to_be_encrypted.txt").read()
data = zlib.compress(text) # normaly much shorter than text

# ... encrypt data with your AES code
# text can be retrieved with zlib.decompress(data)

This technique won't help if your data is already in compressed format (.zip, .jpg, ...)

Thank you, did that, I'm sorry for wasting your time, I should have said that is used zlib.One question about this , is it possible that pickling the text read from the file might increase it's size?

Thank you, did that, I'm sorry for wasting your time, I should have said that is used zlib.One question about this , is it possible that pickling the text read from the file might increase it's size?

Yes I think it is possible, but not significantly. Pickle is not a compression algorithm, it's a persistence algorithm adapted to python data structures. It has nothing to do with zlib or gzip.

Yes I think it is possible, but not significantly. Pickle is not a compression algorithm, it's a persistence algorithm adapted to python data structures. It has nothing to do with zlib or gzip.

I know but I am doing this :

text=file.read()                      
pickled_text=pickle.dumps(text, -1)                               
compressed_text=zlib.compress(pickled_text)

That is why I asked.And please, could you tell me how to edit the code so that is shows the number of the line?Like you did.
LE: found how

I know but I am doing this :

text=file.read()                      
pickled_text=pickle.dumps(text, -1)                               
compressed_text=zlib.compress(pickled_text)

That is why I asked.And please, could you tell me how to edit the code so that is shows the number of the line?Like you did.
LE: found how

Pickling a string does not seem to be a good idea. Your combination of pickle and compress may be less efficient than a single compression.

>>> from pickle import dumps
>>> s = "hello world"
>>> p = dumps(s, -1)
>>> len(p)
18 # > len(s) !
>>> len(s)
11
>>> repr(p)
"'\\x80\\x02U\\x0bhello worldq\\x00.'"

pickling the string only added some noise (the info needed to tell python that the pickled object is a string).

pickling the string only added some noise (the info needed to tell python that the pickled object is a string).

Thanks for that! I really missed that one, I modified the code, I gained 1 sec while running the app on a 2 page txt file, so it's a good gain.