Overview
This lecture introduces the field of cryptography, covers the course structure, and previews foundational concepts such as pseudo-randomness and stream ciphers for encryption.
Course Structure and Focus
- The course teaches how to use cryptographic systems to protect computer system information.
- The first half focuses on secure communication using a shared secret key against powerful adversaries.
- The second half covers public-key techniques for secure key generation and exchange.
- Real-world protocols and common mistakes in existing cryptographic systems are analyzed.
- Optional programming projects and open problems are included for practical learning.
Introduction to Cryptography
- Cryptography is the science of securing communication and protecting information from unauthorized access.
- It is indispensable for computer security and privacy in the modern world.
- The course starts with an overview of cryptography’s purpose and fundamental problems.
Stream Ciphers and Pseudo-randomness
- Stream ciphers are introduced as an initial example of encryption mechanisms.
- The concept of pseudo-randomness is explored for its use in encryption algorithms.
- Basic definitions of secure encryption are discussed to build foundational understanding.
Key Terms & Definitions
- Cryptography — the study of techniques for secure communication in the presence of third parties.
- Stream Cipher — an encryption algorithm that encrypts data one bit or byte at a time using a key stream.
- Pseudo-randomness — the property of appearing random, used in cryptography to generate unpredictable sequences.
- Public-key Cryptography — a cryptographic system using pairs of keys: public (shared) and private (kept secret).
Action Items / Next Steps
- Review the course overview and syllabus for a detailed outline.
- Watch the next lecture: "What is Cryptography?"
- Prepare to learn basic definitions and examples of secure encryption.