The long-awaited lesson on cryptography has finally arrived – Cryptography!
I had hoped to avoid too much math, and luckily, I got my wish. While we covered some basic algorithms, we didn’t dive too deep into complex topics. One concept I was particularly nervous about was Diffie-Hellman—the key exchange protocol—but surprisingly, it wasn’t as difficult as I anticipated. It did take some time to fully understand, though, and I’ve only just scratched the surface. The deeper complexities are something I’ll definitely need to explore further down the road.
To start at the beginning, we learned about plaintext and ciphertext. Plaintext refers to the original, unencrypted data—like a simple text message or a file. Ciphertext, on the other hand, is the encrypted version of the plaintext, making it unreadable without the proper key. In essence, encryption transforms plaintext into ciphertext to protect the information during transmission or storage.
Next, we delved into symmetric and asymmetric encryption, which are two foundational encryption techniques:
- Symmetric encryption involves using the same key for both encryption and decryption. This means that the sender and receiver need to securely share the secret key in advance. It’s fast and efficient but can be risky if the key is intercepted.
- Asymmetric encryption, on the other hand, uses two keys: a public key (used for encryption) and a private key (used for decryption). The public key is freely shared, while the private key remains secret. This method is more secure, as there’s no need to exchange private keys, but it can be slower than symmetric encryption.
We also had a really fun exercise where we worked in pairs to encrypt and send messages using GPG (GNU Privacy Guard). GPG is a tool that implements asymmetric encryption using public and private keys. Here’s an example of how we generated a key pair using GPG:
Generate a key pair:
gpg --full-generate-keyExport the public key:
gpg --armor --export [your-email@example.com] > public_key.ascEncrypt a message:
echo "Hello, this is a secret message" | gpg --encrypt --armor --recipient [partner-email@example.com] > encrypted_message.ascDecrypt a message:
gpg --decrypt encrypted_message.ascIt was an exciting, hands-on way to learn about encryption and how GPG can be used for secure communication. Cryptography is definitely a field I’m eager to dive deeper into!
