Randomised web numbers are too easy to guess

Previously unknown encryption flaw could mean data is stolen more readily, claim researchers

Encryption

A group of security researchers has revealed that the randomised numbers used to encrypt data on the web could be too weak to offer high levels of protection.

The flaw, which prevents servers from generating strong encryption, was discovered by security researchers Bruce Potter and Sasha Moore, who presented their research at the annual Black Hat conference in Las Vegas.

Potter explained that the randomly generated data strings are produced by the server, which detects when certain computer behaviour such as mouse movements and keyboard strokes are made. It converts these into ones and zeros and moves this into a pool of data, which is called upon when security functions are needed.

He used the example of a pack of cards to explain how the numbers are selected, saying an unshuffled pack has low randomisation (entropy) because it is easy to predict in what order the cards would be dealt. Data pools used for encryption should have a high entropy, because there is such a wide variety of numbers to be chosen.

But, the entropy of widely-used Linux web servers is lower than first thought because the machines from which the data comes from are not creating enough information to increase the randomisation. The knock-on effect is that systems are struggling to obtain reliable seeds from which to build secure randomised numbers from, which can make the sequence of the strings easier to guess.

According to Potter, this research has shed light on previously unknown aspects of how encryption works on many popular web servers.

"This seemed like just an interesting problem when we got started but as we went on it got scary ... because when you have unknowns in crypto that's when things go sideways," Potter said.

Featured Resources

BCDR buyer's guide for MSPs

How to choose a business continuity and disaster recovery solution

Download now

The definitive guide to IT security

Protecting your MSP and your customers

Download now

Cost of a data breach report 2020

Find out what factors help mitigate breach costs

Download now

The complete guide to changing your phone system provider

Optimise your phone system for better business results

Download now

Recommended

Best Linux distros 2021
operating systems

Best Linux distros 2021

7 May 2021
Data breach exposes widespread fake reviews on Amazon
data breaches

Data breach exposes widespread fake reviews on Amazon

7 May 2021
TsuNAME vulnerability could enable DDoS attacks on major DNS servers
distributed denial of service (DDOS)

TsuNAME vulnerability could enable DDoS attacks on major DNS servers

7 May 2021
What are SSH keys?
cyber security

What are SSH keys?

7 May 2021

Most Popular

KPMG offers staff 'four-day fortnight' in hybrid work plans
flexible working

KPMG offers staff 'four-day fortnight' in hybrid work plans

6 May 2021
16 ways to speed up your laptop
Laptops

16 ways to speed up your laptop

29 Apr 2021
Qualcomm modem flaw puts millions of Android users at risk
Google Android

Qualcomm modem flaw puts millions of Android users at risk

6 May 2021