What do I learn?

Digital information are ubitiquous. They appear in various forms, such as the data stored in cloud, the messages sent back and forth between the smartphone and Web application service, or the activity post in a social network. We observe a growing demand for digital information in an intensity almost comparable to elementary resources. Such a demand turns precious, exclusive information into assets with a remarkable value, and companies in possession of the information to major players of our economy and society. Securing information thus from competetors, national security agencies or cyberattackers is a crucial requirement when it comes to building, implementing or deploying a digital system and security by design turns into a game changing feature. 

Contemporary cryptography introduces concepts to protecting information. In fact, all well-established information security technologies of today build upon some cryptographic concept. Understanding cryptographic algorithm design, essential security properties and the reason why cryptographic algorithms are deemed secure is a fundamental step towards the goal of designing, implementing and deploying secure information technologies.

The lecture is devoted to study the foundations of contemporary cryptography. We explore the basic concepts of cryptography, incuding

  • One-way functions
  • Hard-core predicates
  • Pseudorandom generators and functions
  • Message Authentication schemes
  • Symmetric encryption
  • Trapdoor functions
  • Digital signatures
  • Assymteric encryption
  • Hybrid encryption

Our treatment of cryptography is formal. It is an neccessary requirement. Imprecise deployment of cryptographic concepts may lead to vulnerable implementations and render the whole idea of securing the system void.  

What can I do with this knowledge?

You learn the basics of theorectical cryptography. Like any science with solid foundations you will get to know a theory in which a cryptographic concept is a stepping stone for another one. You learn fundamental cryptographic algorithms, how to construct them, and to analyze security. Most notably you will deobfuscate the "magic" of cryptography and obtain the powerful skill of understanding why a cryptographic concept gives the desired security guarantees and why it is really hard to break security. You will turn into an information security expert. You will be confident to choose the right crytogtraphic concept in order to secure an information system and understand many important cryptographic applications, such as SSL/TLS, bitlocker or bitcoin.

Rules of the Game

You are given problem sets each week you have to solve before the forthcoming class. A tutor will check your solutions and give feedback. Towards the end of the course you write a final exam. You pass the course, if

">50% of problem sets are solved correctly" AND ">50% of the exam is solved correctly" 

Recommended Books

Jonathan Katz and Yehuda Lindell: Introduction to Modern Cryptography (2nd Edition)   Dan Boneh and Victor Shoup: A graduate course in Cryptography (v0.2)    

Online Courses

You may have a look at Jonathan Katz's lecture on coursera. Dan Boneh's cryptography course is also pretty awesome.

Research Papers

  • Whitfield Diffie, Martin E. Hellman: New directions in cryptography. IEEE Trans. Information Theory 22(6): 644-654 (1976)
  • Oded Goldreich and Leonid Levin: A hard-core predicate for all one-way functions. STOC, 1989
  • Johan Hastad, Russell Impagliazzo, Leonid A. Levin, and Michael Luby: A Pseudorandom Generator from any One-way Function. SIAM J. Comput., 28(4), 1364–1396
  • Oded Goldreich, Shafi Goldwasser and Silvio Micali: How to Construct Random Functions, Journal of the ACM, vol.33, no.4, 792-807
  • Shafi Goldwasser and Silvio Micali, Probabilistic Encryption, Special issue of Journal of Computer and Systems Sciences, Vol. 28, No. 2, 270-299
  • Shafi Goldwasser, Silvio Micali, and Ronald L. Rivest: A Digital Signature Scheme Secure Against Adaptive Chosen-Message Attacks. SIAM J. Comput., 17(2), 281–308
  • Danny Dolev, Cynthia Dwork and Moni Naor: Non-malleable cryptography. STOC, 1991
  • Mihir Bellare, Anand Desai, David Pointcheval, and Phillip Rogaway: A concrete security treatment of symmetric encryption. FOCS ,1997
  • Mihir Bellare, Anand Desai, David Pointcheval, and Phillip Rogaway: Relations among Notions of Security for Public-Key Encryption Schemes, CRYPTO, 1998