NYU Cryptography Group at Courant Institute
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Transcript of NYU Cryptography Group at Courant Institute
• Faculty:– Yevgeniy Dodis
[email protected]– Victor Shoup
NYU Cryptography Group at Courant
Institute• Students:
– Nelly Fazio– Michael
Freedman– Anca Ivan– Antonio Nicolosi– Roberto Oliveira– Shabsi Walfish
• Meet every week– This semester Friday, 1pm, room 101
• Drop by!– Contact me to be put on the mailing list
http://www.scs.cs.nyu.edu/crypto
Cryptography Reading Group
Our Main Goals
• Improving the security and/or efficiency of cryptographic applications
• Designing new, provably secure cryptographic primitives
• Formalization and rigorous analysis of common cryptographic practices
• Protecting against key exposure
• Secure distributed/multiparty computation
Our Style: Provable Security
• Formal definition for the cryptographic task at hand
• A concrete scheme which provably satisfies the above definition, assuming some commonly believed and well studied mathematical problem is “hard”
• Ensures that the only way to break the cryptographic scheme is to break a well studied mathematical problem, which is very unlikely (e.g., factoring)
• Gives much higher guarantee/assurance than commonly utilized “heuristic” approaches
Crypto Skills
• Creativity: open mind, love for puzzles
• Formalism (proofs!) and elementary math (number theory, probability)
• Ability to ask interesting questions
• Ability to thinkas a devil…
Some of Our Projects• Signature and Encryption Schemes• Authenticated Encryption• Resilience to Key Exposure• Distributed and Multi-party Cryptography
– Two-party computation
• Digital Right Management• Cryptography with Imperfect Randomness• Ideal Hash Function Methodology• Fault-tolerant Authentication• Privacy and Anonymity …
Some projects I have been involved in @
NYU…Warnings:• Not meant to…
– give formal introduction to cryptography– be crystal clear if you see it for the first time
• Instead…– give vague summary of the “kind” of things I like– emphasize joint works with students and faculty
• Talk to me if interested in details!
• "Exposure-Resilient Functions and All-Or-Nothing Transforms" , Eurocrypt, 2000.
• "On Perfect and Adaptive Security in Exposure-Resilient Cryptography", Eurocrypt, 2001.
• "Exposure-Resilience for Free: the Case of Hierarchical ID-based Encryption", IEEE International Security In Storage Workshop (SISW), 2002.
Partial Key Exposure
Designed new model of key-insulated security, led to intrusion-resilient security
• "Key-Insulated Public Key Cryptosystems", Eurocrypt, 2002.
• "Strong Key-Insulated Signature Schemes", Workshop on Public Key Cryptography (PKC), 2003.
• "Intrusion-Resilient Public-Key Encryption", RSA Conference, Cryptography Track (CT-RSA), 2003.
Key Evolving Schemes
• Max Krohn, David Mazieres and Antonio Nicolosi, "Proactive Two-Party Signatures for User Authentication", Network and Distributed System Security Symposium (NDSS), 2003.
• Anca Ivan, "Proxy Cryptography Revisited", Network and Distributed System Security Symposium (NDSS), 2003.
• "Generic Two-party CCA-secure Encryption Scheme and its Applications", manuscript
Two-Party Schemes
• "On the Security of Joint Signature and Encryption", Eurocrypt, 2002.
• "Concealment and Its Applications to Authenticated Encryption", Eurocrypt, 2003.
• Michael Freedman and Shabsi Walfish, "Parallel Signcryption with OAEP, PSS-R and other Feistel Paddings", submitted to Crypto 2003.
• Michael Freedman and Shabsi Walfish, "Universal Padding Schemes", manuscript.
• "Parallel Authenticated Encryption", manuscript.
Authenticated Encryption
• Nelly Fazio, "Public Key Broadcast Encryption for Stateless Receivers", ACM Workshop on Digital Rights Management, 2002.
• Nelly Fazio, "Public Key Broadcast Encryption Secure Against Adaptive Chosen Ciphertext Attack", Workshop on Public Key Cryptography (PKC), 2003.
• Nelly Fazio, "Fully Scalable Public-Key Traitor Tracing", submitted, 2003.
• Nelly Fazio, "Forward-Secure Broadcast Encryption", manuscript.
Digital Right Management
• "New Imperfect Random Source with Applications to Coin-Flipping", International Colloquium on Automata, Languages and Programming (ICALP), 2001.
• Joel Spencer, "On the (non-)Universality of the One-Time Pad", Foundations of Computer Science (FOCS), 2002.
• Roberto Oliveira, "On Extracting Private Randomness over a Public Channel", manuscript.
Imperfect Randomness
• "Parallel Reducibility for Information-Theoretically Secure Computation", Crypto, 2000.
• "Efficient Construction of (Distributed) Verifiable Random Functions", Workshop on Public Key Cryptography (PKC), 2003
• “Distributed Block Ciphers", manuscript
Distributed Cryptography
• "Lower Bounds for Oblivious Transfer Reductions", Eurocrypt, 1999.
• "A Cryptographic Solution to a Game Theoretic Problem", Crypto, 2000.
• "On the Power of Claw-Free Permutations", Conference on Security in Communication Networks (SCN), 2002
Cryptography: Other…
Can moderate taxes force selfish users minimize global traffic and congestion?
• Richard Cole, "Pricing Network Edges for Heterogeneous Selfish Users", Symposium on Theory of Computing (STOC), 2003.
• Richard Cole, "The Cost of Taxes for Selfish Routing", ACM Conference on Electronic Commerce (EC), 2003.
Algorithmic Game Theory
My Other Interests
• Algorithms: randomized and approx. algorithms, network design…
• Coding Theory: relates to crypto too• Complexity Theory:
derandomization…• Combinatorics and Graph Theory• Anything else that has proofs and
requires problem solving…
Recap of some recent group activities
Signature & Encryption• First provably secure and yet efficient
signature and encryption schemes [CS98, CS99, CS02]– lead to new standards for PKI
• Efficient schemes utilizing ideal hash functions [Sho00, Sho01, DR02, DFW03, DFJW03]
• Signature / encryption schemes with extended functionalities [CS03, DF03, NKDM03]
Authenticated Encryption
• First formal modeling of public-key authenticated encryption (signcryption) [ADR02]
• Parallel authenticated encryption [ADR02, DFW03, DFJW03, Dod03a]
• Designing authenticated encryption for long messages [DA03]
Key Exposure Protection
• Exposure-resilient functions and All-or-nothing transforms [CDH00, DSS01]
• Key-insulated signature and encryption scheme [DKXY02, DKXY03]
• Intrusion-Resilient Encryption [DKY03]• Remotely-Keyed Encryption [DA03]• Server-Aided/Proxy/Proactive
Cryptography [NKDN03, ID03, DY02]
Distributed Computation
• Byzantine Agreement [CKS00, CKPS01, KS01]
• Threshold Cryptosystems [SG98,Sho00]• Distributed verifiable random functions
and block ciphers [Dod03b, DY03]• Joint generation of special RSA keys
[ACS02]• Two-party computation [NKDN03, ID03]• Concurrent protocols composition
[DM00]
Some Other Projects• Digital right management [DF02,
DF03, DFKY03]• Ideal Hash Function Methodology
[Dod03b, DS03]• Basing Cryptography on Imperfect
Randomness [DS02, DO03]• Cryptography and Game Theory
[DHR00]• …