Sony FeliCa does not provide any official docs on which cryptographic functions are used for their NFC cards. They got some docs explaining that they do mutual authentication, but there is no official paper explaining what crypto with which parameters they use at all. It's unknown which random generators etc. are used as well and there is no code to check what they exactly do.
So I was wondering if someone knows what crypto they use? If there is maybe any code which includes their authentication I would like to have a look at it and check if these cards are really as safe as they say.
Maybe I should specify the question a bit more. It's public known that FeliCa uses DES and AES encryption, but no specification is given. So let's just discuss DES cards.
- Is 3DES used?:
- ECB or CBC mode?
- How do they calculate the keys for the first step of their mutual authentication? Why is that necessary todo?
- How do they generate a new challenge? Is it just some random?
- Is maybe just DES-Encryption used?
- Would that mean cards could be bruteforced?