Advanced Topics in Modern Cryptography

Advanced Topics in Modern Cryptography

 

(Summer Term 2019)

CISPA / Saarland University

 

Presentations/Dates

- 6th June: Oblivious Transfer and extensions

- 13 June: Garbled Circuits

- 13 June: Optimizing Semi-Honest Secure Multiparty Computation for the Internet

- 27th June: LEGO

- 27th June: DUPLO

- 4th July: Fully Homomorphic Encryption over the Integers – and bootstrapping

- 4th July: TFHE library and GSW13 scheme

 

Overview

Fully-Homomorphic Encryption (FHE) schemes and Multi-Party Computation (MPC) are fundamental tools in modern cryptography. For decades FHE and MPC schemes have been abstract concepts living in the realm of cryptographic theory. In recent years those systems have seen major improvements in terms of efficiency and practicality. In short, FHE and MPC schemes have become practical enough to be considered for applications in private delegation of machine learning models, and applications to privacy-preserving distributed Genome-wide association studies. This seminar is concerned with the fundamentals and practical aspects of FHE and MPC. We will heavily focus on the general understanding of the presented schemes, their implementation, and concrete efficiency. By the end of the seminar participants should possess fundamental knowledge about FHE and MPC and should know the state-of-the-art libraries and developer tools which are nowadays available. Among others, we will discuss cryptosystems and their implementations which are part of
- FHEW/TFHE (FHE library)
- HElib (IBM)
- SEAL (Microsoft)
- SPDZ, Mascot, Overdrive (MPC)
- Other open source tools

---

Logistics

Location: E9 1, CISPA Building, Room 0.06

Seminars will take place on Thursdays at 14:00 - 16:00. Exact dates will be established during the seminar kick-off

Seminar kick-off: Thursday, 18 April 2019, 14:00 - 16:00

Contact: Kamil Kluczniak (kamil.kluczniak@cispa.saarland)

---

Course structure and grading

 

- Regular attendance of all sessions of the seminar according to the list of attendees. 
- Successful seminar talk on the assigned topic. The presentation can be up to 45 minutes. The presentation is followed by a discussion on the presented topic with the presenter which can be up to 15 minutes. Presentation language is English; Discussion is in English or German (depending on the audience).
- A presentation should include prototypes and/or brief benchmarks of the selected tools or libraries.
- A short written report, lecture notes or "how-to" (depending on the topic) of the presented topic.
- Active and meaningful contributions to all discussions of the seminar.

 

---

Registration and pre-requisites

 

Students are required to have basic knowledge of Linear and Abstract Algebra, Cryptography (Fundamentals), C/C++ programming.
In some cases, Python may be useful.

Registration is handled via https://seminars.cs.uni-saarland.de/

---

Topics and Materials

The topic and materials below may slightly change after the lecture kick-off.

Additional materials will come soon...

 

1. Oblivious Transfer and extensions (reserved)

- Paper “More Efficient Oblivious Transfer Extensions with Security for Malicious Adversaries”: https://eprint.iacr.org/2015/061.pdf

- Library: https://github.com/encryptogroup/OTExtension

- Youtube: https://www.youtube.com/watch?v=fcQfkTvjnIw

- Additional materials:

* Talk on Oblivious transfer: https://www.youtube.com/watch?v=pIi-YTBBolU

* Oblivious transfer at Stanford: https://crypto.stanford.edu/pbc/notes/crypto/ot.html

* Wikipedia: https://en.wikipedia.org/wiki/Oblivious_transfer

 

2. Garbled Circuits (reserved)

- Just garble library website: http://cseweb.ucsd.edu/groups/justgarble/

- Paper Efficient Garbling from a Fixed-Key Blockcipher: https://eprint.iacr.org/2013/426.pdf

- Additional materials: A Gentle Introduction to Yao’s Garbled Circuits: http://web.mit.edu/sonka89/www/papers/2017ygc.pdf

- Youtube:

* https://www.youtube.com/watch?v=s9AUtz1na5E 

* https://www.youtube.com/watch?v=IQgsHxTfXXw

- Wikipedia: https://en.wikipedia.org/wiki/Garbled_circuit

 

3. Optimizing Semi-Honest Secure Multiparty Computation for the Internet (reserved)

- Paper: https://eprint.iacr.org/2016/1066

- Youtube: https://www.youtube.com/watch?v=Day4JzECUoc

 

4. LEGO (reserved)

- Paper: https://eprint.iacr.org/2016/1069.pdf

- Code: https://github.com/AarhusCrypto/TinyLEGO

- Youtube: https://www.youtube.com/watch?v=eFvNvcDq1j0

- Protocol Based on:

* "Lego for Two Party Secure Computation"

* "TinyLEGO: An Interactive Garbling Scheme for Maliciously Secure Two-Party Computation"

 

5. DUPLO (reserved)

- Paper: https://eprint.iacr.org/2017/344.pdf

- Code: https://github.com/AarhusCrypto/DUPLO

- Youtube: https://www.youtube.com/watch?v=hyV2TrI9rmw

 

6. Fully Homomorphic Encryption over the Integers – and bootstrapping (reserved)

- Paper https://eprint.iacr.org/2009/616.pdf

- Youtube: https://www.youtube.com/watch?v=Y1TxCiOuoYY&t=6211s

- No code available - small proof of concept implementation in Python

 

7. TFHE library and GSW13 scheme (reserved)

- Present GSW13 scheme: Homomorphic Encryption from Learning with Errors: Conceptually-Simpler, Asymptotically-Faster, Attribute-Based.

- Paper: https://eprint.iacr.org/2013/340.pdf

- TFHE Library at: https://tfhe.github.io/tfhe/

- Youtube video: https://www.youtube.com/watch?v=O8IvJAIvGJo&t=

 

7.5. FHEW library and bootstrapping in less than 0.1 secconds

FHEW library: https://github.com/lducas/FHEW

- Paper: https://eprint.iacr.org/2014/816.pdf

- Talk is very ambitious (optional)

 

8. Helib and the BGV scheme

- The BGV scheme: Fully Homomorphic Encryption without Bootstrapping

- Paper: https://eprint.iacr.org/2011/277.pdf

- Library: https://github.com/shaih/HElib

 

9. SEAL and the BFV scheme

- The BFV scheme: Somewhat Practical Fully Homomorphic Encryption

- Fully Homomorphic Encryption without Modulus Switching from Classical GapSVP

- Paper: https://eprint.iacr.org/2012/078.pdf

- SEAL library: https://www.microsoft.com/en-us/research/project/microsoft-seal/

- Youtube: https://www.youtube.com/watch?v=S_Bhir1bst0

 

10. SPDZ-2

- Library: https://github.com/bristolcrypto/SPDZ-2

- Paper: https://eprint.iacr.org/2011/535.pdf 

- Youtube: https://www.youtube.com/watch?v=P8sofNziSiw and https://www.youtube.com/watch?v=N80DV3Brds0 and https://www.youtube.com/watch?v=Ce45hp24b2E

- Additional materials:

*  https://eprint.iacr.org/2012/642.pdf