What Is Encryption

🔑 What Is Encryption?

• Definition: Encryption is the process of converting readable information (plaintext) into unreadable format (ciphertext) using algorithms and keys.
• Purpose: Protects confidentiality, integrity, and authenticity of data.
• How it works:
  1. Sender uses an encryption algorithm and a key to transform plaintext into ciphertext.
  2. Ciphertext is transmitted or stored.
  3. Recipient uses a decryption key to convert ciphertext back into plaintext.

🧩 Types of Encryptions

• Symmetric Encryption: Same key for encryption and decryption (e.g., AES).
• Asymmetric Encryption: Public key for encryption, private key for decryption (e.g., RSA, ECC).
• Hashing (related but different): One‑way transformation, used for integrity checks (e.g., SHA‑256).

🔐 Password Encryption (Process)

When we talk about passwords, encryption or hashing is critical for security. Here’s the step‑by‑step process:

1. Input plaintext password
   • User types "MyPassword123" into a login form.
2. Algorithm selection
   • System chooses an algorithm:
     • Symmetric (AES) or asymmetric (RSA) for transmission.
     • Hashing (SHA‑256, bcrypt, PBKDF2) for storage.
3. Key or salt generation
   • Encryption uses keys.
   • Hashing often adds a salt (random string) to strengthen security.
4. Transformation
   • Plaintext → Ciphertext or Hash.
   • Example: "MyPassword123" → a5f3c6a11b... (SHA‑256 hash).
5. Storage/Transmission
   • Stored in database as hash (not plaintext).
   • Transmitted over network with encryption (TLS/SSL).
6. Verification
   • User enters password again.
   • System applies the same algorithm.
   • Compares result with stored hash/ciphertext.
   • If match → access granted.

⚙️ Where Encryption Is Used

• Data at rest: Files, databases, storage devices.
• Data in transit: HTTPS, VPNs, messaging apps.
• Authentication: Passwords, digital signatures, certificates.
• Cloud security: Protects sensitive data stored remotely.

📌 Benefits

• Confidentiality → prevents unauthorized access.
• Integrity → ensures data hasn’t been altered.
• Authentication → confirms identity.
• Compliance → meets legal/regulatory requirements.