Karim Eldefrawy

Cryptography, Cybersecurity, Privacy

Co-founder and CTO at Confidencial.io
2017-2021: SRI
2011-2016: HRL Laboratories
2006-2010: PhD@UC Irvine

Scientific curiosity

Brief Bio

Karim Eldefrawy, Ph.D., is the Co-founder & CTO of Confidencial.io. Prior to that he was a Principal Computer Scientist at the Computer Science Laboratory (CSL) at SRI (previously Stanford Research Institute). His R&D interests focus on secure and privacy-preserving computation for distributed systems, computer-aided formal verification of cryptographic algorithms and protocols, and security in cyber-physical and embedded systems. His interests also include post-quantum cryptography and recent work in quantum communication and quantum algorithms. His research has been funded by the Defense Advanced Research Project Agency (DARPA), the Department of Homeland Security (DHS), the Intelligence Advanced Research Projects Activity (IARPA), the National Science Foundation (NSF), the US AirForce (AFWERX), and Boeing and General Motors. His work has received the 2024 Test of Time Award by the Internet Society’s Network and Distributed System Security Symposium (NDSS). Karim authored over 100 scientific works (75+ peer-reviewed papers and book chapters, and 31 granted and 10+ pending patents). His opinions and writing on various cybersecurity topics have been featured on Forbes and other venues. Karim served on technical program committees of top academic conferences on security and cryptography and was the information director of ACM Transactions on Privacy and Security (formerly ACM TISSEC) from 2011 to 2015. Karim taught security and cryptography courses at the University of California at Irvine (UCI) and the University of San Francisco (USF).

Contact

  • Startup: {firstname_dot_lastname} + {@} + {name_of_my_startup_dot_io}
  • Research: {firstname_dot_lastname} + {@} + {sri_dot_com}
  • Personal: {lastname} + {@} + {email_of_most_famous_search_engine}
  • Personal Encrypted: {lastname} + {@} + {proton_email}

Cryptography Arcade

Cryptography Arcade
CRYPTOGRAPHY ARCADE™

A PROACTIVE SYSTEMS LAB PRODUCTION

SECURE BOOT // ENTROPY CHECK // SYSTEM READY

Cryptography Arcade // Proactive Secret Sharing (PSS) + Proactive MPC (PMPC)

OUTREFRESH THE MOBILE ADVERSARY

LOCK A RANDOMIZED REJUVENATION SCHEDULE BEFORE THE VIRUS APPEARS. TOO SLOW: IT OBTAINS FOUR COMPATIBLE SHARES. TOO AGGRESSIVE: RECOVERY OVERLAP BREAKS QUORUM.

SET REJUVENATION SCHEDULE

RANDOM DRAW // NO DUPLICATES // REJUVENATION TIME 2.2S

This schedule keeps five parties online during one repair round, with no planned overlap.

Time
000.0
Epoch
01
Current shares
0 / 4
Online
7 / 7
4-OF-7 PROACTIVE NETWORK NEXT DRAW 02.4 // SPEED 1.0x // SCORE 00000
A seven-party connected network game. Choose a rejuvenation schedule and start the defense.

P1 through P7 are online; the adversary path is hidden.

SET SCHEDULE // LOCK CONTROLS // REVEAL HIDDEN ATTACK PATH

SCHEDULE LOCKS AT START // VIRUS DISPLAY IS PLAYBACK ONLY // RESET TO REPROGRAM

HOW THE TOY PROTOCOL WORKS

This is an illustrative hybrid of proactive share refresh and randomized proactive recovery, not a protocol simulator. The mobile adversary hops only along network links and retains every distinct current-epoch share it reads. Four compatible shares reveal this toy secret. At each committed maintenance time, a fair random draw sends the chosen parties offline for recovery. If a quorum remains, the toy abstracts a coordinated system-wide refresh at that pulse: the epoch advances, obsolete honest-party state is assumed securely erased, and old exposures no longer combine with new ones. Selected parties rejoin clean after recovery. If fewer than four parties remain online—even temporarily—the toy computation loses availability. Taking too many parties down does not cryptographically destroy the secret; it removes the live 4-party quorum needed to use or continue it. Real PSS and proactive MPC protocols have separate privacy, correctness, robustness, recovery, erasure, communication, and network assumptions.