# Tag Info

7

I think this question is setting up a false dichotomy. It's not that a researcher has an opinion as to whether they prefer software or hardware implementations. The choice of implementation depends on the requirements of the specific cryptosystem you're building. For example, if you're designing a system to encrypt voice traffic on a mobile phone network, ...

6

As pointed in this comment, using a huge random key for a sound block cipher is an excellent defense to resist ASIC/GPU attacks. Each bit added doubles the effort required. If an adversary was able to build $10^{12}$ ASICs each capable of testing $10^{12}$ keys per second, odds of finding a 128-bit key by brute force running that for a decade are less than ...

5

A video camera can obtain entropy, but only at a fairly low rate and only if allowed to see "unusual" scenes… like someone making funny faces, unusual movements, etc. Of course, this only works in a room with no video bugs. Theoretical explanations… Depending on your knowledge-range, the following sources may be able to explain ways webcams can be used ...

3

Don't think you've missed something. How do they keep these systems from being broken by someone just looking at the information in the smartcard that houses the key? Those systems have indeed been (and frequently are) broken via Hardware reverse-engineering. Therefore I would chime in with your "not secure". OTOH: decrypting AV signals isn't like ...

3

The access codes were recently leaked (by whom, I don't know). My Yubikey is listed and I can confirm that the access codes were necessary and sufficient to reprogram it. You can change or remove the access code as part of reprogramming too. The leak doesn't make the Yubikeys useless in the extremely unlikely event of Gox rising from the flames — no ...

3

No, you will not be ble to abuse challenges in that way. You may be thinking about e.g. raw RSA, where signing and decryption are mathematically similar. However, this is not possible in FIDO U2F: All the defined signature algorithms use SHA256 on the signed data, meaning that you'd have to brute force search for something that produces the correct ...

3

I'm not a researcher in the field of cryptography. With that out of the way, the most obvious reasons I can think of are: Software is more universally deployable, increasing the target audience of some solution. With a hardware solution, potential customers may be forced to invest a huge amount of money to deploy it. A software solution is probably cheaper ...

2

One technology that is required for such a token is the provisioning of the keys for the One-Time-Password (OTP)-based algorithm and then you have to also pick an OTP algorithm. I co-chaired the group in the IETF who standardized these protocols (at the time when the RSA patents expired). Here is a pointer to the group called KEYPROV: ...

2

At one point, most music legally sold digitally was protected by DRM (all iTunes music, for instance). Eventually the labels backed down and started allowing the music to be published DRM-free. So yes the music industry has attempted this, but it encountered all of the fundamental problems with DRM and was abandoned. Crypto fundamentally can't protect you ...

1

NIST has a lot of information on testing random number generators at http://csrc.nist.gov/groups/ST/toolkit/rng/index.html that might be of value to you.

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