If we want to send the message ‘11010’ (26) E and D are the private and public keys.Find E coprime to Z (that is gcd(Z,E) = 1).Maximum message length we can encrypt is log(N).The data that we encrypt with one key can only be decrypted with the other key so if someone wants to send me a message, he encrypt the message with my public key, to decrypt it back i need to use my private keyĮvery user has a private and public key pair, minimum 512 bit. We need a secure way to exchange the keys.Īsymmetric encryption works with 2 keys for each side – private key that we need to save and never send it to anyone and public key that we can publish anywhere.

We can’t send it over the network in plain text because any “men in a middle” can read it. The big problem with symmetric encryption is how to share the keys between each pair. Other symmetric algorithms available in P圜rypto are DES, 3DES, RC2, RC4 and more – see Crypto.Cipher module documentation for details Now the other side need the key to decrypt the message using the same Key and IV: plain=crypt(msg) the Key is shared between the pair, The IV can be different for each message.

To use AES we need to create Key and IV (initalization vector). Generally a good algorithm should be easy to use (encryption and decryption) and hard to hack Example – AES The big challenge is to create algorithm that will not simply hacked. It is very easy to create a new symmetric algorithm, for example – change every second bit (1 => 0, 0 => 1). To encrypt and decrypt the data we use the same key: The simplest way to encrypt and decrypt data is to use a symmetric encryption. P圜rypto package supports encryption and decryption with symmetric and asymmetric algorithm, hashing with various methods, digital signature, random numbers and more. In this post I’m using P圜rypto package but there are more packages you can use to do the same (less or more) Installing P圜rypto # pip install pycrypto With python cryptographic packages we can encrypt and decrypt data using various methods, we can also sign data, create hash, use secure communication and more. While working with data, storing in files, sending to a remote machine and so on, we sometimes need to encrypt the data to prevent unauthorised access. Python is a great programming language for data analysis, web development, networking and more.

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