Breaking Discrete Logarithm Security: Insights from the Logjam Attack π
Explore how the Number Field Sieve algorithm is used to compromise discrete logarithm-based security, highlighting the techniques behind the Logjam attack and implications for cryptographic protocols.

CryptoClear
1.7K views β’ Jan 30, 2021

About this video
A high-level overview of the Number Field Sieve approach used in the Logjam attack described in the "Imperfect Forward Secrecy" paper by Adrian et al., CCS 2015.
We dive into Discrete Logarithms, why it is supposed to be a tough problem, and how the common practice of reusing the same finite fields to avoid weakening the security of Diffie-Hellman key exchange actually results in weakening the security of Diffie-Hellman key exchange.
Continue learning:
- The paper and more material: https://weakdh.org
- Some criticism: https://nohats.ca/wordpress/blog/2015/10/17/66-of-vpns-are-not-in-fact-broken/
- Math is Fun has a great introduction to properties of logarithms: https://www.mathsisfun.com/algebra/logarithms.html
- Find out what keys are common today: https://www.ssllabs.com/ssl-pulse/
- Learn all about primes: https://www.springer.com/gp/book/9780387252827
Bad Ideas - Silent Film Dark by Kevin MacLeod is licensed under a Creative Commons Attribution 4.0 licence. https://creativecommons.org/licenses/by/4.0/
Source: http://incompetech.com/music/royalty-free/index.html?isrc=USUAN1100489
Artist: http://incompetech.com/
We dive into Discrete Logarithms, why it is supposed to be a tough problem, and how the common practice of reusing the same finite fields to avoid weakening the security of Diffie-Hellman key exchange actually results in weakening the security of Diffie-Hellman key exchange.
Continue learning:
- The paper and more material: https://weakdh.org
- Some criticism: https://nohats.ca/wordpress/blog/2015/10/17/66-of-vpns-are-not-in-fact-broken/
- Math is Fun has a great introduction to properties of logarithms: https://www.mathsisfun.com/algebra/logarithms.html
- Find out what keys are common today: https://www.ssllabs.com/ssl-pulse/
- Learn all about primes: https://www.springer.com/gp/book/9780387252827
Bad Ideas - Silent Film Dark by Kevin MacLeod is licensed under a Creative Commons Attribution 4.0 licence. https://creativecommons.org/licenses/by/4.0/
Source: http://incompetech.com/music/royalty-free/index.html?isrc=USUAN1100489
Artist: http://incompetech.com/
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Video Information
Views
1.7K
Likes
81
Duration
18:14
Published
Jan 30, 2021
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