0.  Introduction and round of introductions

1.  Symmetric Encryption

• Kerckhoff's principle
• Storage and management of passwords
• How is encryption defined
• Definition: "What does secure mean?"
• Classification of attacks on encryption
• Definition of "Perfect Secrecy" and "Semantic Security"
• stream cipher
• Cryptographically secure random numbers
• block cipher Encryption modes (ECB, CBC, CTR, GCM, ...)
• What is an "Initialization Vector"?
• key lengths Why padding?
• Motivation for Message Authentication Codes
• hash functions
• Message Authentication Codes (MACs)
• Authenticated Encryption
• Key generation and delivery
• key management
• Password-based key generation
• entropy
• Storage and management of passwords

2.  Asymmetric Encryption

• What is a "Public/Private Key" for?
• Brief introduction to mathematics relevant to number theory
• Differences to symmetric
• encryption Diffie-Hellman key exchange
• RSA
• DSA
• elliptical curves
• padding process
• key lengths
• key generation
• Again: "What does safe mean"?
• digital signatures
• Digression: logs
  

3.  TLS und PKIs

• TLS goals and introduction
• TLS - The Record Protocol
• TLS - The handshake protocol
• Encrypted records
• TLS best practices
• Certificates & PKI
• OCSP & CRLs

• Comprehensive overview of the use of cryptography in practice
• Concrete recommendations for algorithms and their use
• Symmetric & asymmetric cryptography as well as TLS and PKIs

This seminar conveys the background and requirements in a more contemporary way cryptography. The basics required for this are introduced step by step and build on each other so that the connections are always recognizable remain. The focus is on practical application and implementation of the topics, the theory is deepened by practical exercises in Java.

Developers, administrators and architects who want secure handling of cryptographic procedures, as well as project managers who want to learn more about the background of cryptographic standards or guidelines. School mathematics is sufficient for the course.