Public-key Cryptosystem | Free Online Course | Alison

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Cryptography: Public-key Cryptosystem

Learn about the Cryptographic Applications of the Public-key Cryptosystem in this free online course

Free Course
In this free online course in Cryptography, you will learn about the Cryptographic Applications of the Public-key Encryption Scheme and the Discrete Logarithm Assumptions. You will also gain an insight into the CCA-Security for Public-Key Cryptosystems and the CCA insecurity of the El Gamal Public-Key Cipher. This course will benefit anyone who wants to gain more knowledge about the concepts of the Public-Key Cryptosystems and Public Key Ciphers.
  • Duration

    5-6 Hours
  • Assessment

  • Certification

  • Responsive

  • Publisher






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This free online course in Cryptography, highlights the cryptographic applications of the Discrete Logarithm Assumptions and the Public-Key Encryption Scheme. In the first section, you will learn about the definition of CPA security and CCA security in the context of Public-Key Encryption. You will also learn about the El Gamal Encryption Scheme, the CPA-security of the El Gamal Cipher and the solutions to the problems encountered when the El Gamal Encryption Scheme is adopted. The generic construction of a Public-Key Cryptosystem from the one-way trap-door permutation, will also be highlighted in the first section of the course. You will also be shown the notion of COA (CPA)-secure variants of the RSA Public-key Cryptosystem.

In the next section, you will be introduced to the concept of Hybrid Public-Key Encryption where you will learn about Key Encapsulation Mechanism Paradigm, the Computational Diffie-Hellman-based Key Encapsulation Mechanism in the Random Oracle Model, and the Diffie-Hellman based Key Encapsulation Mechanism in the standard model. The course will discuss the generic construction of CCA-Secure Public-Key Cipher from any CCA-Secure Key Encapsulation Mechanism and CCA-Secure Symmetric-Key Cipher. Thereafter, you will also learn about the CCA secure instantiations of the Hybrid Public-Key Cryptosystem based on Diffie-Hellman Problems.

Lastly, you will learn about the Malleability of the Plain RSA cipher, CCA-insecurity of padded RSA and the Instantiation of the Public-Key Cryptosystem based on RSA Assumptions. This course is a great starting point for anyone who is looking to pursue a career in Cryptography. It will also be highly relevant to those who want to learn more about Public-Key Cryptosystems and Ciphers. Why wait, start this course today!

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Learning Outcomes

Upon successful completion of this course, you should be able to:

  • Compare the differences between COA Security in the Public and Private-Key World
  • State similarities between RSA Assumption and Factoring Assumption 
  • Discuss the Hybrid Public-Key Encryption Scheme
  • Define the properties of Digital Signatures
  • Outline similarities between Digital Signatures and MAC
  • Discuss the Schnorr Identification Scheme
  • State the fundamental theorem of Arithmetic

  • Summarise properties of the Zero-Knowledge Proof Protocol


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