[Colloq] Colloquium Talk: Key Derivation Without Entropy Waste - Prof. Yevgeniy Dodis - Wednesday, May 8th, 2:00pm

[Jessica Biron]

Colloquium Talk: Key Derivation Without Entropy Waste 

Professor Yevgeniy Dodis 

Wednesday May 8th 
2:00pm 366 WVH 

Abstract: 

We revisit the classical question of converting an imperfect source X 
of min-entropy k into a usable m-bit cryptographic key for some 
underlying application P. If P has security delta (against some class 
of attackers) with a uniformly random m-bit key, we seek to design a 
key derivation function (KDF) h that allows us to use R=h(X) as the 
key for P and results in comparable security delta' close to delta. 

Seeded randomness extractors provide a generic way to solve this 
problem provided that k > m + 2*log(1/delta), and this lower bound on 
k (called "RT-bound") is known to be tight in general. Unfortunately, 
in many situation the "waste" of 2*log(1/delta) bits of entropy is 
significant, motivating the question of designing KDFs with less waste 
for important special classes of sources X or applications P. 
I will discuss several positive and negative results in this regard. 
The most surprising of them will be a positive result for all 
unpredictability applications P, yielding a provably secure KDF with 
entropy "waste" only loglog(1/delta) - an expenential improvement over 
the RT-bound. 

Bio: 

Yevgeniy Dodis is a Professor of computer science at New York
University. Dr. Dodis received his summa cum laude Bachelors degree in
Mathematics and Computer Science from New York University in 1996, and
his PhD degree in Computer Science from MIT in 2000.  Dr. Dodis was a
post-doc at IBM T.J.Watson Research center in 2000, and joined New
York University as an Assistant Professor in 2001. He was promoted
to Associate Professor in 2007 and Full Professor in 2012.

Dr. Dodis' research is primarily in cryptography and network security.
In particular, he worked in a variety of areas including
leakage-resilient cryptography, cryptography under weak randomness,
cryptography with biometrics and other noisy data, hash function and
block cipher design, protocol composition and information-theoretic
cryptography. Dr. Dodis has more than 100 scientific publications at
various conferences, journals and other venues, has been on program
committees of many international conferences (including FOCS, STOC,
CRYPTO and Eurocrypt), and gave numerous invited lectures and courses
at various venues.

Dr. Dodis is the recipient of National Science Foundation CAREER
Award, Faculty Awards from IBM, Google and VMware, and Best Paper
Award at 2005 Public Key Cryptography Conference. As an undergraduate
student, he was also a winner of the US-Canada Putnam Mathematical
Competition in 1995.