Hello, key point of this problem is to implement a two keys 3DES algorithm with CBC, key size 112 and block size 64. Lang C++ or C Here are some hints from the university: To achieve all the goals, use the cryptographic capabilities that are provided by the Microsoft CryptoAPI interface. Task options are presented in table 1. Implement a secure file sharing software. In function programs include encrypting and decrypting files on disks with symmetric encryption algorithm. 1. Symmetric encryption algorithm is shown in table. 1. 2. Use a session key to encrypt the file symmetrically KS symmetric algorithm.

3. Show two options for generating a session key KS: 1 option. by using a cryptographic key management system; Option 2. By password phrase. The last name in Latin will be a password phrase. 4. Select a file to encrypt. The file is located locally on the computer user. 5. Encrypt the file with the KS session key.

6. To securely store the KS session key together with the encrypted one use asymmetric encryption with a key pair current system user. The user creates a key pair RSA size 1024 bits. Creates a certification request based on the public key and passes it to the local certification authority. Gets from the local center certification of the H.509 certificate of his public key and the X.509 certificate public key certification authority. Certificate X.509 of its open the key must be placed in the WINDOWS repository.

7. Remove the recipient's public key from the certificate X.509. 8. Encrypt the session key with the RSA public key recipient and add an encrypted session key to the encrypted file. 9. Save the ciphertext in the specified file.