Skip to content

Encryption Methods

Today we will learn about encryption methods, symmetric and asymmetric encryption, and their applications.

Explanation

Encryption is the process of converting plaintext into ciphertext to protect data confidentiality. It ensures that only authorized parties can access the information.

Key Concepts:

Symmetric Encryption: Uses the same key for encryption and decryption (e.g., AES).
Asymmetric Encryption: Uses a public key for encryption and a private key for decryption (e.g., RSA).
Hashing: One-way encryption for integrity (e.g., SHA-256).

Technical:

How Encryption Works:

Symmetric: Key is shared secretly. Fast for large data. Asymmetric: Public key encrypts, private key decrypts. Slower, used for key exchange. Hybrid systems combine both for efficiency.

Security Benefits:

Protects data at rest and in transit, prevents unauthorized access, and ensures integrity through hashing.

How to setup one properly:

General Best Practices

  1. Use strong algorithms (AES-256, RSA-4096).
  2. Manage keys securely (use HSMs or key managers).
  3. Rotate keys regularly.
  4. Implement end-to-end encryption where possible.

Client (Encryption Tools)

Use encryption on your local machine.

Linux/macOS

  1. Use GPG for asymmetric encryption:
  2. Install: sudo apt install gnupg (Linux) or brew install gnupg (macOS).
  3. Generate keys: gpg --full-generate-key
  4. Encrypt file: gpg --encrypt --recipient [email protected] file.txt
  5. For symmetric: Use OpenSSL: openssl enc -aes-256-cbc -salt -in file.txt -out file.enc
  6. For full disk: Use LUKS on Linux or FileVault on macOS.

Windows

  1. Use BitLocker for disk encryption:
  2. Enable in Control Panel > BitLocker Drive Encryption.
  3. For files: Use 7-Zip with AES encryption.
  4. Install GPG4Win for asymmetric encryption.
  5. Generate keys via Kleopatra.
  6. Encrypt: Right-click file > Sign/Encrypt.

Note: Back up keys securely; loss means data loss.

Server Setup

Implement encryption on servers.

Linux

  1. Use LUKS for disk encryption during install or cryptsetup.
  2. For network: Use TLS/SSL with certificates.
  3. Generate certs with Let's Encrypt or OpenSSL.
  4. Encrypt databases with tools like pgp_sym_encrypt for PostgreSQL.

Windows

  1. Enable BitLocker on server drives.
  2. Use EFS (Encrypting File System) for files.
  3. For web servers: Configure SSL in IIS with certificates.

Note: Use certificate authorities for trust.

Samples:

Example GPG Encrypted File

-----BEGIN PGP MESSAGE-----
hQEMA5rX8QJzQ5QZAQgAk...
-----END PGP MESSAGE-----

Example OpenSSL Symmetric Encryption

openssl enc -aes-256-cbc -salt -in plaintext.txt -out encrypted.enc

(Decrypt with -d flag.)

Example RSA Key Pair

Public Key:

-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA...
-----END PUBLIC KEY-----

Private Key (DO NOT SHARE):

-----BEGIN PRIVATE KEY-----
MIIEvQIBADANBgkqhkiG9w0BAQEFAASCBKcwggSjAgEAAoIBAQC...
-----END PRIVATE KEY-----
  • Use AES for symmetric, RSA/ECC for asymmetric.
  • Tools: GPG, OpenSSL, VeraCrypt.
  • Enable encryption by default.
  • Stay updated on vulnerabilities (e.g., Heartbleed).