Hashing vs encryption

Hashing

Hashing is a process of converting data (like a file or a message) into a fixed-size string of characters, which typically appears random.

Common hashing algorithms - SHA-256, MD5

Encryption

Encryption is the process of converting plaintext data into an unreadable format, called ciphertext, using a specific algorithm and a key. The data can be decrypted back to its original form only with the appropriate key.

Key Characteristics:

• Reversible: With the correct key, the ciphertext can be decrypted back to plaintext.
• Key-dependent: The security of encryption relies on the secrecy of the key.
• Two main types:
  • Symmetric encryption: The same key is used for both encryption and decryption.
  • Asymmetric encryption: Different keys are used for encryption (public key) and decryption (private key).

Symetric encryption

• Code

  const crypto = require('crypto');
  
  // Generate a random encryption key
  const key = crypto.randomBytes(32); // 32 bytes = 256 bits
  const iv = crypto.randomBytes(16); // Initialization vector (IV)
  
  // Function to encrypt text
  function encrypt(text) {
      const cipher = crypto.createCipheriv('aes-256-cbc', key, iv);
      let encrypted = cipher.update(text, 'utf8', 'hex');
      encrypted += cipher.final('hex');
      return encrypted;
  }
  
  // Function to decrypt text
  function decrypt(encryptedText) {
      const decipher = crypto.createDecipheriv('aes-256-cbc', key, iv);
      let decrypted = decipher.update(encryptedText, 'hex', 'utf8');
      decrypted += decipher.final('utf8');
      return decrypted;
  }
  
  // Example usage
  const textToEncrypt = 'Hello, World!';
  const encryptedText = encrypt(textToEncrypt);
  const decryptedText = decrypt(encryptedText);
  
  console.log('Original Text:', textToEncrypt);
  console.log('Encrypted Text:', encryptedText);
  console.log('Decrypted Text:', decryptedText);

Asymetric encryption