CRYPTOGRAPHYHow does it impact cyber security and why you need to know more?

WHAT YOU DON'T KNOW ABOUT CRYPTOGRAPHY

Alice computes gab = (gb)a mod p, and Bob computes gba = (ga)b mod p

C= M e % n

y2 = x3 + Ax + B

And why it can hurt you

Kerhoff

Euler

Ferm

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WHO IS THE SPEAKER?

19 Books

29 industry certifications

2 Masters degrees

6 Computer science related patents

Over 20 years experience, over 15 years teaching/training

Helped create CompTIA Security+, Linux+, Server+. Helped revise CEH v8

Frequent consultant/expert witness

Teaches crypto around the world

www.chuckeasttom.com

chuck@chuckeasttom.com

WHAT DOES CRYPTO DO FOR YOU?

Provide data Confidentiality

Data integrity

Identification and Authentication

Non- repudiation

WHAT ARE THE LIMITS OF MOST SECURITY PROFESSIONALS CRYPTO KNOWLEDGE

General description of symmetric crypto (AES, DES, Blowfish)

General description of assymetric (Diffie Hellman, RSA, DSA, and maybe ECC)

General description of digital signatures

General description of digital certificates

General description of protocols such as TLS

WHY?

Why learn crypto? Kerkhoff’s principle

Bad crypto solutions

Dual_EC_DRBG backdoor

Is RSA Secure enough?

KERKHOFF’S PRINCIPLE

“A cryptosystem should be secure even if everything about the system, except the key, is public knowledge”

-August Kerkhoff

The EnigmaDS story http://money.cnn.com/2011/09/02/technology/unhackable_code/

BAD CRYPTO SOLUTIONS

Windows SALT What is SALT And why hashing needs it?

How does it go wrong?

Keep it secret

Has to be simple enough to be fast

Has to be complex enough to not be ‘guessable’

Poor random number generators

How to select hard drive/file encryption

DUAL_EC_DRBG BACKDOOR

In 2013 Edward Snowden revealed that it had a backdoor however:

In 2004 suspicions of this where around the crypto community

In 2006 multiple papers are published suggesting this.

In 2006 Bruce Schneier blogged about it.

The Cyber Security community may have been in the dark on this issue, but the crypto community was not.

WHAT ABOUT CRYPTOGRAPHIC BACKDOORS?

What can you do?

Can you prevent them even if you don’t know they are there?

PROBLEMS WITH RSA

The most widely used asymmetric cryptographic algorithm, may not be secure enough.

IS RSA STILL SECURE?

Heninger and Shacham Zhao and Qi Yeh, Huang, Lin, and Chang Hinek

HENINGER AND SHACHAM

Heninger and Shacham (2009) found that RSA implementations that utilized a smaller modulus were susceptible to cryptanalysis attacks. A smaller modulus can increase the efficiency of an RSA implementation, but as Heninger and Shacham (2009) showed, it may also decrease the efficacy.

HENINGER AND SHACHAM

Heninger and Shacham (2009) utilized the fact of the smaller modulus to reduce the set of possible factors, thus decreasing the time needed to factor the public key of an RSA implementation. It is in fact a common practice to use a specific modulus e = 216 + 1= 65537 (Heninger & Shacham, 2009). If an RSA Implementation is using this common value for e, then factoring the public key is a much simpler process

ZHAO AND QI

Zhao and Qi (2007) also utilized implementations that have a smaller modulus operator. The authors of this study also applied modular arithmetic, a subset of number theory, to analyzing weaknesses in RSA. Many implementations of RSA use a shorter modulus operator in order to make the algorithm execute more quickly.

RSA RESOURCES

Hinek, M. (2009). Cryptanalysis of RSA and its variants. England: Chapman and Hall.

Heninger, N., Shacham, H. (2009). Reconstructing RSA private keys from random key bit. Advances in Cryptology Lecture Notes in Computer Science, 1 (1). doi:10.1007/978-3-642-03356-8_1.

Yeh, Y., Huang, T., Lin, H., Chang, Y. (2009). A study on parallel RSA factorization. Journal of Computers, 4 (2), 112-118. doi:10.4304/jcp.4.2.112-118

Zhao, Y., Qi, W. (2007). Small private-exponent attack on RSA with primes sharing bits. Lecture Notes in Computer Science, 2007, 4779 (2007) 221-229. doi: 10.1007/978-3-540-75496-1_15

HOW TO LEARN MORE?

http://www.cryptocorner.com/ Professor Dan Boneh’s course online

https://class.coursera.org/crypto-preview/lecture Modern Cryptography: Applied Mathematics for

Encryption and Information Security by Chuck Easttom from McGraw Hill (out by August 2015)

Applied Cryptography: Protocols, Algorithms, and Source Code in C by Bruce Schneier

Secret History: The Story of Cryptography by Bauer

Modern Cryptanalysis: Techniques for Advanced Code Breaking by Swenson