Cryptography Systems

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Cryptography Systems

• Secure Real-Time Transport Protocol (SRTP)
• LDAP Secure (LDAPS)
• HyperText Transfer Protocol Secure (HTTPS)
• Post Office Protocol (POP)
• Internet Message Access Protocol (IMAP)
• Secure Multipurpose Internet Mail Extensions (S-MIME)

Attacks on Cryptographic Algorithms

• Cryptographic Attacks
  • Brute Force Attack
  • Birthday Attack
  • Meet-in-the-Middle Attack
  • Man-in-the-Middle Attack (On-Path)
  • Dictionary Attack
  • Replay Attack
  • Bit-Flipping Attack
  • Frequency Analysis Attack
  • Implementation Attacks
• Cryptanalysis

Quantum Computers and Symmetric Crypto

• Grover’s Algorithm
  • best available quantum algorithm for attacking a generic symmetric cipher
    • provides a square root speedup compared to an exhaustive search
  • for symmetric cipher with -bit key, this reduces the exhaustive search work-factor to about
  • e.g., for AES with 256-bit key, has a vulnerable work-factor of
    • which is still not feasible today and probably never will be
• thus symmetric ciphers are not seriously threatened by quantum computing

Virtual Private Networks

• Virtual Private Network (VPN)

Email Security

• Email Security
  • Sender Policy Framework (SPF)
  • DomainKeys Identified Mail (DKIM)
  • Domain-based Message Authentication, Reporting, and Conformance (DMARC)

Cryptographic Hash Applications

• Blockchain
• Cryptocurrency