About

a picture of me

UPDATE: I have recently graduated form UCLA, and will soon start a post-doc position at Princeton University.


I am a PhD student in the Computer Science Department at UCLA. I work in the Theory and Cryptography lab with Professor Rafail Ostrovsky and Professor Amit Sahai.


I received B.Sc. in Computer Engineering in 2003, and M.Sc in Computer Science in 2009, both from Technion, Israel. My M.Sc. research dealt with the security of theoretical and realistic Quantum Key Distribution Schemes, and was performed under the supervision of Professor Tal Mor.


Contact information


3771 Boelter Hall
Computer Science Department
University of California, Los Angeles (UCLA)
Los Angeles, CA 90095
email: gelles (e) ucla.edu
        

 

Research Interests

My research interests are: Coding (esp. coding for Interactive Communication), Computability and Complexity;
Cryptography; and Quantum Cryptography;

 

 

Publications

Journal Papers

“Optimal Coding for Streaming Authentication and Interactive Communication”.
Matthew Franklin, Ran Gelles, Rafail Ostrovsky, Leonard J. Schulman.
Accepted to IEEE Trans. on Information Theory, 2014.
“Attacks on Fixed Apparatus Quantum Key Distribution Schemes”.
Michel Boyer, Ran Gelles, Tal Mor.
Physical Review A, (90):012329, 2014. [arXiv:1312.0979]
“How to catch L2-Heavy Hitters on Sliding Windows”.
Vladimir Braverman, Ran Gelles, Rafail Ostrovsky.
(Invited) Accepted to a Special Issue of TCS, 2014. [arXiv:1012.3130]
“Efficient Coding for Interactive Communication”.
Ran Gelles, Ankur Moitra, Amit Sahai.
IEEE Trans. on Information Theory, 60(3), pages 1899–1913, 2014. [paper]
“Position-Based Quantum Cryptography: Impossibility and Constructions”.
Harry Buhrman, Nishanth Chandran, Serge Fehr, Ran Gelles, Vipul Goyal, Rafail Ostrovsky, Christian Schaffner.
SIAM Journal on Computing, 43(1), pages 150–178, 2014.
“Security and Composability of Randomness Expansion from Bell Inequalities”.
Serge Fehr, Ran Gelles, Christian Schaffner.
Physical Review A, (87):012335, 2013. [open-access] (also: arXiv:1111.6052)
“Security of the Bennett-Brassard Quantum Key Distribution Protocol Against Collective Attacks”.
Michel Boyer, Ran Gelles, Tal Mor.
Algorithms, 2(2), pages 790–807, 2009. [open-access]
“Semiquantum Key Distribution”.
Michel Boyer, Ran Gelles, Dan Kenigsberg, Tal Mor.
Physical Review A, (79):032341, 2009. [arXiv:0812.4835]

Conference Papers

“Efficient Error-Correcting Codes for Sliding Windows”.
Ran Gelles, Rafail Ostrovsky, Alan Roytman.
SOFSEM 2014, 40th International Conference on Current Trends in Theory and Practice of Computer Science. LNCS 8327, pages 258-268. [paper]
“Private Interactive Communication Across an Adversarial Channel”.
Ran Gelles, Amit Sahai, Akshay Wadia.
ITCS 2014, Proceedings of the 5th Conference on Innovations in Theoretical Computer Science, ACM, pages 135-144. [ePrint 2013/259]
“Optimal Coding for Streaming Authentication and Interactive Communication”.
Matthew Franklin, Ran Gelles, Rafail Ostrovsky, Leonard J. Schulman.
CRYPTO 2013, Part II, LNCS 8043, pages 258–276. [ECCC TR12–104], [watch]
“How to catch L2-Heavy Hitters on Sliding Windows”.
Vladimir Braverman, Ran Gelles, Rafail Ostrovsky.
COCOON 2013, 19th International Conference on Computing and Combinatorics. LNCS 7936, pages 638–650. [arXiv:1012.3130]
“Attacks on Fixed Apparatus Quantum Key Distribution Schemes”.
Michel Boyer, Ran Gelles, Tal Mor.
TPNC 2012, 1st International Conference on the Theory and Practice of Natural Computing. LNCS 7505, pages 97–107. [arXiv:1312.0979]
“On the Security of Interferometric Quantum Key Distribution”.
Ran Gelles, Tal Mor.
TPNC 2012, 1st International Conference on the Theory and Practice of Natural Computing. LNCS 7505, pages 133–146. [arXiv:1110.6573]
“Multiparty Proximity Testing with Dishonest Majority from Equality Testing”.
Ran Gelles, Rafail Ostrovsky, Kina Winoto.
ICALP 2012, Part II, LNCS 7392, pages 537–548. [eprint 2012/378]
“Efficient and Explicit Coding for Interactive Communication”.
Ran Gelles, Ankur Moitra, Amit Sahai.
FOCS 2011, Proceedings of the IEEE 52nd Annual Symposium on Foundations of Computer Science, pages 768–777. [watch]
Preliminary version arXiv:1104.0739 (cs.DS)
“Position-Based Quantum Cryptography: Impossibility and Constructions”.
Harry Buhrman, Nishanth Chandran, Serge Fehr, Ran Gelles, Vipul Goyal, Rafail Ostrovsky, Christian Schaffner.
CRYPTO 2011, LNCS 6841, pages 429–446. [arXiv:1009.2490], [watch] (Chris)

Preprints

“Adaptive Protocols for Interactive Communication”.
Shweta Agrawal, Ran Gelles, Amit Sahai.
arXiv:1312.4182 (cs.DS), 2013.
“A Little Honesty Goes a Long Way: The Two-Tier Model for Secure Multiparty Computation”.
Juan A. Garay, Ran Gelles, David S. Johnson, Aggelos Kiayias, Moti Yung.
eprint 2014/209, 2014.

 

Teaching

  • Spring 2011: CS181 - Formal Languages and Automata Theory (UCLA).
  • Winter 2011: CS181 - Formal Languages and Automata Theory (UCLA).
  • Fall 2010: CS181 - Formal Languages and Automata Theory (UCLA).
  • Winter 2003: CS236364 - Operating Systems Structure (Technion).

 







PhD comics - life in grad-school.
Tips for writing a PhD thesis (and other helpful stuff).
AMS Statement - on alphabetical author list in TCS (as a branch of mathematics).
לא מדויק - הבלוג המתמטי של גדי אלכסנדרוביץ
חיפושים כמשל - הבלוג הלשוני של אמיר אהרוני
מגילת המועמד, מגילת התקן, מגילת דני עקשני, מגילת הבניין 1, ו־מגילת האתיקה, – הומור משובח מבית מדרשו של פרופ' עירד יבנה