Play all

Intro

ECDSA and Schnorr Signatures

Risk of Biased/Leaky Randomness

Randomness Failure in the Real World

Contributions

ECDSA signing

Side channel attacks in scalar multiplication

Experimental setup

Cache-timing attacks on prime curves

Cache-timing attacks on binary curves

Software countermeasures

Main takeaways

The problem we tackle: 1-bit of nonce leakage

The problem we tackle: less than 1-bit of nonce leakage

How to attack the HNP

New attack records for the HNP!

The Fourier analysis-based attack?

Bleichenbacher's Attack High-level Overview

Step 1. Bias Function (Essentially DFT)

Handy Form of the Bias Function

Modeling Erroneous Input

Step 2. Detecting the Bias Peak (Naive Approach)

Problem: Naive Approach is inefficient!

Solution: Collision Search to Broaden the Peak

Collision Search Problem in Bleichenbacher's Framework

K-list Sum Algorithm for GBP (eg, X = 4)

Applying Howgrave-Graham and Joux's K-list Sum Algorithm

Unified Time Memory Data Tradeoffs

Tradeoff Graphs for 1-bit Bias

Experimental Results on Full Key Recovery

Conclusion

Description:

Explore a comprehensive presentation on LadderLeak, delivered by Diego F. Aranha and Akira Takahashi at the Workshop on Attacks in Cryptography (WAC 2020). Delve into the intricacies of ECDSA and Schnorr signatures, examining the risks associated with biased or leaky randomness in cryptographic systems. Discover real-world examples of randomness failures and learn about contributions to the field. Investigate side-channel attacks in scalar multiplication, including cache-timing attacks on prime and binary curves. Analyze the problem of nonce leakage, exploring attacks on the Hidden Number Problem (HNP) and Bleichenbacher's attack. Gain insights into Fourier analysis-based approaches, collision search techniques, and the K-list sum algorithm. Examine unified time-memory-data tradeoffs and experimental results on full key recovery. Enhance your understanding of cryptographic vulnerabilities and potential countermeasures in this in-depth 46-minute talk.

LadderLeak

TheIACR

Add to list

#Information Security (InfoSec) #Cybersecurity #Side Channel Attacks #Computer Science #Cryptography #Engineering #Electrical Engineering #Signal Processing #Fourier Analysis #Schnorr Signatures