RSA Algorithm Implementation in C

RSA is an asymmetric cryptographic algorithm used by modern computers to encrypt and decrypt messages. Asymmetric means that there are two different keys. This is also called public key cryptography, because one of the keys can be given to anyone. The other key must be kept private.


This article do not cover operation of RSA algorithm. We suggest to go through very simple explanation given on Wikipedia for detailed step-by-step explanation.

Following is the implementation of RSA cryptographic algorithm in C. The program expects an input file input.txt which should contain the plain text and generates an output file decipher.txt which contains our decrypted text. It also generates an intermediary file cipher.txt which contains the encrypted text in bits.



Above program is tested in Windows environment using Code::Blocks 16.01.

Thanks for reading.

Please use our online compiler to post code in comments.
Like us? Please spread the word and help us grow. Happy coding 🙂

Leave a Reply

Notify of