encryption_decryption_server

• Summary:

  • This is an encryption and decryption application written in C using the one-time pad encryption and decryption algorithm.
  • The program consists of 5 files:
    • enc_server.c
    • dec_server.c
    • enc_client.c
    • dec_client.c
    • keygen.c

• Usage details:

  • Please have the C gcc compiler installed on your system.
  • Please run the Makefile file to have the c files compiled into executable files.
  • Once the executable files are created, please initial the program in the following order:
  • Start the enc_server file by entering the following command into a terminal window:
    • ./enc_server 4321 &
    • Note: This starts the encryption program at port 4321 in the background. It is possible to use any other port as the input port.
  • Start the dec_server file by entering the following command into a terminal window:
    • ./dec_server 1234 &
    • Note: this starts the decryption program at port 1234 in the background. It is possible to use any other port as the input port.
  • Create a text file containing a key by running the keygen file using the following command:
    • ./keygen 99999 > sample_key
    • Note: this creates a file named "sample_key" containing a key consisting of uppercase alphabet letters and the space character of length 99999
  • Encrypt a plaintext file using the enc_client program by entering the following command:
    • ./enc_client plaintext1 sample_key 4321 > sample_cipher
    • Note: this creates a text file named "sample_cipher" containing the ciphertext corresponding to the sample plaintext file named "plaintext1" using the encryption server initialized and key created in the previous steps. It is also possible to enter a custom plaintext file consisting of only uppercase alphabet letters and the space character.
  • Decrypt a ciphertext file using the dec_client program by entering the following command:
    • ./dec_client sample_cipher sample_key 1234 > sample_result
    • Note: this creates a text file named "sample_result" containing the resulting plaintext corresponding to the previously created sample ciphertext file named "sample_cipher" using the decryption server initialized and key created in the previous steps. The sample_result file should be identical to the original plaintext1 file if every step has been executed correctly.