Reverse Engineering a Bank's Security Token 55
An anonymous reader writes "An engineer from Brazil has posted a technical walkthrough of how he was able to reverse engineer his bank's code-generating security token. He found a way to accurately generate his unlock codes with some custom code and an Arduino clone. (Don't worry: his method doesn't give him access to anybody else's codes.) 'Every exception thrown by this piece of code is obfuscated, as well as many of the strings used throughout the code. That is a major roadblock, since exception messages and strings in general are a great way of figuring out what the code is doing when reverse engineering something. Luckily, their developers decided to actually show useful text when a problem occurs and an exception gets thrown, so they wrapped those obfuscated strings with a.a, presumably a decryption routine that returns the original text. That routine is not too straightforward, but it is possible to get a high level understanding of what it is doing.'"
Re:Read between the lines (Score:5, Informative)
Unsolvable even with specialized hardware, you just increase the costs for both yourself and any potential attacker... Probably increasing your own costs far more than that of the attacker.
This is not a security breach (Score:4, Informative)
FYI: This is not a security breach. The algorithm is not supposed to be the secret. There are lots of android/iphone apps to do this, and most of them use HOTP or TOTP which is an IETF standard algorithm. The security is in the secret key that is generated when you run the app the first time. This key is synchronized between the server and the key generator when it is setup.