Over the past few days, I worked on practical cybersecurity and cloud security exercises focused on data encryption and secure file transfer.
The first part of the practical involved encryption in practice. I created a test file containing sample customer information and used OpenSSL to encrypt the file with AES-256-CBC. I then decrypted the file and used SHA-256 hashing to verify that the decrypted version was identical to the original file. This helped demonstrate how encryption can protect sensitive information while maintaining data integrity.
I also performed the same encryption and decryption process using Blowfish. During the exercise, I encountered an issue because Blowfish is disabled by default in modern OpenSSL versions. I resolved this by loading the OpenSSL legacy provider. Afterward, the file was successfully encrypted and decrypted, and SHA-256 hashes confirmed that no data was lost or corrupted.
The second part focused on secure file transfer and the security weaknesses of FTP. I set up an FTP server using vsftpd and used Wireshark to capture the network traffic while logging in and transferring information. The packet capture demonstrated that FTP sends usernames and passwords in plaintext, meaning an attacker monitoring the network could read the credentials directly.
I then repeated the process using SFTP over SSH. Unlike FTP, the SFTP traffic was encrypted after the SSH key exchange, and Wireshark could no longer display the usernames, passwords, or file-transfer commands as readable text. This demonstrated how SSH-based file transfer provides confidentiality and integrity for data in transit.
Overall, the practical sessions gave me hands-on experience with AES encryption, Blowfish, OpenSSL, SHA-256 hashing, FTP, SFTP, SSH, vsftpd, and Wireshark. The exercises helped me understand the importance of protecting sensitive data both when it is stored and when it is being transferred across a network.