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{ Category Archives } Crypto

Did the UK create a new kind of “Crypto Mule”?

It’s almost always the case that a new or changed law means that there is a new kind of criminal, because there is by definition a way to contravene the new law. However, when the law allows the real criminals to hide behind others who will take the fall, that’s probably a failure in the […]

On how to get crypto wrong

I’ve said time and time again: don’t write your own encryption algorithm. Once you’ve chosen an existing algorithm, don’t write your own implementation. Today I had to look at an encryption library that had been developed to store some files in an app. The library used a custom implementation of SHA256-HMAC, and a custom implementation […]

On the extension of code signing

One of the public releases Apple has made this WWDC week is that of Safari 5, the latest version of their web browser. Safari 5 is the first version of the software to provide a public extensions API, and there are already numerous extensions to provide custom functionality. The documentation for developing extensions is zero-cost, […]

Regaining your identity

In my last post, losing your identity, I pointed out an annoying problem with the Sparkle update framework, in that if you lose your private key you can no longer post any updates. Using code signing identities would offer a get-out, in addition to reducing the complexity associated with releasing a build. You do already […]

Losing your identity

Developers make use of cryptographic signatures in multiple places in the software lifecycle. No iPad or iPhone application may be distributed without having been signed by the developer. Mac developers who sign their applications get to annoy their customers much less when they ship updates, and indeed the Sparkle framework allows developers to sign the […]