Encryption and Security

Introduction

• Speaker: Mia Gilner, Computer Science major at UC Berkeley
• Works for the Department of Defense focusing on information security

The Internet and Private Data

• Internet is an open system
• We exchange private data (credit card numbers, bank info, passwords, emails)
• Encryption helps keep this data secret

Encryption and Decryption

• Encryption: Scrambling or changing a message to hide the original text
• Decryption: Unscrambling the message to make it readable
• Historical use: Caesar Cipher by Julius Caesar
  • Substitutes each letter with a letter a certain number of steps down the alphabet (key)
  • Easily breakable by trying all 26 possible keys

Enhancing Encryption

• Shift each letter by a different amount using a multi-digit key
  • Makes guessing the key much harder
  • Example: 10-digit key (10 billion possible solutions)
• Modern encryption uses 256-bit keys
  • Takes trillions of trillions of years to crack even with supercomputers

Symmetric vs Asymmetric Encryption

• Symmetric Encryption: Same key for encrypting and decrypting (e.g., Caesar Cipher)
  • Key must be agreed upon in private
• Asymmetric Encryption: Uses public and private keys
  • Public key: Can be shared with anyone, used to encrypt data
  • Private key: Not shared, used to decrypt data
  • Example: Mailbox analogy for understanding public key cryptography

Modern Use and Importance

• Foundation of secure messaging on the Internet (e.g., SSL, TLS)
• Indicators of secure connections: HTTPS in browser
• Increasing need for secure data transmission
• Continuous evolution: Developing new encryption methods as computers become faster

Conclusion

• Encryption is essential for protecting private data on the internet
• Ongoing challenge: Staying ahead of advancements in computing power