The Price of Privacy
Written by Dominik Joe Pantůček on 2018-10-25
securityprivacyLast week I gave a talk about key management in an environment where you cannot trust your computing devices. Read on to learn more about the price of privacy and implications of some design decisions when it comes to your privacy and identity.
I really enjoyed my days at Prague College[1] and Teesside University[2] as a student and after taking a year off to focus on Cryptoucan™ development - as you might have noticed - I returned as a lecturer[3]. As a lecturer, I was asked by the head of our college to give a talk at our computing mini-conference[4].
It was a pleasant surprise to see that also some of my students have arrived and were eager not only to listen but also to discuss the matters. In my talk, I went through the comparison of information confidentiality with privacy and the comparison of information integrity and digital identity. Of course this was just to introduce the attendees that public-key cryptography can be used for enforcing privacy and identity policies effectively.
As the full title of my talk was "Secure key management in the wake of latest cross-platform threats", I followed on with explanation on how current malware targets multiple platforms at once. It tries to steal your login credentials for online banking website and cooperates with another malware in your mobile phone to intercept SMS with authentication code. This way, it can completely gain control over your assets - although you have used something that looks like a well-designed two-factor authentication. Truth is, such schemes are not well designed - at least that is my opinion which I always happily present and defend.
If you opt for public-key cryptography instead of two-factor authentication, you gain more control over your digital identity and you should be able to retain more privacy. There is only one problem: you need to ensure that the private key of your key pairs is protected. In addition to it, you must know how to perform damage control should the key get lost or leaks. Therefore, it must be possible to revoke and simply rotate keys.
It never hurts to repeat what everybody thinks they know. The two approaches to key management. Firstly, the public-key infrastructure[5]. It has its advantages - like being really simple to implement and manage. Typically if you need to handle anything, you just ask CA[6] staff and they take care of your request.
A different approach is to roll-out your own key management. Using the web-of-trust[7] approach and mainly having your own master key in a cold storage[8], that is something that can really get you to a different level of key security. This way, you can revoke compromised keys yourself and you are always able to generate and sign new key afterwards.
But with such scheme, you need to protect your private keys more. Especially the master key. Having the keys on your hard drive sort of beats the purpose. And with the wake of latest cross-platform threats, it is hard to trust your own computing devices. Therefore I - as always - suggested the usage of cryptographic tokens like smart cards or USB appliances.
You might have guessed - even though it is not possible to buy Cryptoucan™ yet, I have shown it to the audience. That should come of no surprise, because only with Cryptoucan™ the keys are really safe and even in case of complete compromise of users' devices, Cryptoucan™ will safely hold the keys and ensure the compromised devices cannot abuse them.
Thank you for staying with us and get ready for more action next week!
References
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Wikipedia contributors. (2018, September 18). Certificate authority. In Wikipedia, The Free Encyclopedia. Retrieved 20:25, October 25, 2018, from https://en.wikipedia.org/w/index.php?title=Certificate_authority&oldid=860112985
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Wikipedia contributors. (2018, September 28). Web of trust. In Wikipedia, The Free Encyclopedia. Retrieved 20:25, October 25, 2018, from https://en.wikipedia.org/w/index.php?title=Web_of_trust&oldid=861520083
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https://trustica.cz/en/2018/09/13/key-management-introduction/