Karim Eldefrawy

Cryptography, Cybersecurity, Privacy Computer Science

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

Scientific curiosity

79peer-reviewed publications 31granted patents 12funded R&D projects 4.7K+Google Scholar citations

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 cybersecurity and cryptography 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

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  • 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

GOAL // KEEP EVERY EPOCH BELOW THE SELECTED SHARE THRESHOLD. A REFRESH CHANGES EVERY SHARE, BUT CORRUPTED PARTIES LEAK THE NEW COLOR IMMEDIATELY; ONLY REJUVENATION REMOVES THE VIRUS.

SET REJUVENATION SCHEDULE

ATTACK PACE IS DRAWN AT RESET // +6% EVERY 15S // SPORADIC BURSTS NEVER EXCEED +30%

Two simultaneous recoveries leave at least four clean helpers while the adversary holds at most three parties.

Time left
01:00.0
Attack pace
0.20 / S
Current shares
0 / 4
Clean helpers
9 / 9
4-OF-9 PROACTIVE NETWORK NEXT REFRESH 03.2 // RATE 0.20/S // SCORE 00000
A nine-party connected network game. Choose a rejuvenation schedule and start the defense.

P1 through P9 are online; the adversary path is hidden.

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

SCHEDULE LOCKS AT START // ONE STATE-PRESERVING PURGE PER RUN // RESET TO DRAW A NEW ATTACK RATE

HOW THE TOY PROTOCOL WORKS

This is an illustrative configurable-threshold Shamir-sharing game, not a protocol simulator. Each epoch uses a fresh degree-two or degree-three polynomial with the same secret at zero, so the selected degree plus one same-color shares reconstruct while one fewer reveal nothing in this toy model. A virus compromise immediately copies that party's current share and persists until the party is rejuvenated. Rejuvenation removes the infection but cannot erase a share already copied by the adversary. At each maintenance pulse, the selected parties begin recovery and every share changes color; any party still corrupted immediately leaks its new share. Old-color shares remain visible in the ledger but cannot combine with a new epoch. Two simultaneous recoveries leave enough clean helpers for the selected threshold while the adversary remains below it. The displayed base compromise rate rises six percent every fifteen seconds and receives occasional short bursts of at most thirty percent. The rate is an upper-bound compromise-attempt pace; graph traversal can revisit an already corrupted party. Once per run, the player may invoke an abstract state-preserving purge that removes every infection and immediately reshares into a fresh epoch; previously copied colors remain archived. Survive the selected one- or two-minute period to win. This models share leakage, not arbitrary Byzantine message forgery: three of nine is exactly one third, not the stricter less-than-one-third active-fault regime. Real proactive secret sharing requires explicit channel, erasure, recovery, correctness, robustness, and adversary assumptions.

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