You could implement it yourself, but Python handily provides a built-in function for this: pow(x, e, n) There is a simple remedy: use modular exponentiation, which keeps the size of the numbers that it is working with low throughout the whole calculation by reducing modulo n as it goes along. This does not finish in a reasonable time. Key = RSA.generate(1024, random_generator) For example, trying it out with 1024bit RSA (the lowest setting!): import Crypto Kenc**d is in general a very big number that takes a long time to compute, and then it takes a long time again to reduce it modulo n. There is a serious problem with this implementation: it computes kenc**d. In this case though, there is a much more efficient solution that is about equally simple, and is probably sufficient.

Usually the most efficient way to perform a non-trivial task is not also the simplest way to do it. #Encrypt something with public key and print to consoleĮncrypted = pub_key.Simple does not mean fast, so you cannot judge performance based on how simple the implementation looks. #Load public key back from file and we only need public key for encryption #Save both keys into some file for future usage if needed #Show the real content of the public part to console #Show the real content of the private part to console, be careful with this! Where the bits is the strength of your key, e.g 2048.Įither way you will have an RSA key object ( _RSAobj) returned, then you can do encryption as the rest of your code did.

Or: key = RSA.generate(bits, randfunc=None, progress_func=None, e=65537) Where the externKey is a String, so you can load the key string from your key File with this way. So what you should do is: key = RSA.importKey(externKey, passphrase=None) Key = RSA.importKey(externKey, passphrase=None)įirst, ,e,d,p,q,u,private> is not a valid key, not sure how you get this, but it is a string representation of your key as a Python object only, the actual key content is not presented, also note that you cannot rebuild the key object with this string representation.īefore you do RSA encrypt with your key, you should import your key from some place like File, Generating In Memory etc. I get a syntax error at line 5 pointing at the ,e,d,p,q,u,private>') I am trying to write a RSA encryption software tool that will use the same key every single time.

Python rsa decryption