Cryptography Stack Exchange
Cryptography Stack Exchange

Questions tagged [cryptographic-hardware]

Cryptographic hardware enables the handling of cryptographic tasks and/or problems using hardware instead of software solutions.

Cryptographic hardware enables the handling of cryptographic tasks and/or problems using hardware instead of software solutions. Some examples of cryptographic hardware are: cryptanalytic devices‎, encryption devices‎, encryption device accessories‎, smart cards‎, etc.

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Technical feasibility of decrypting https by replacing the computer's PRNG

Intel has an on-chip RdRand function which supposedly bypasses the normally used entropy pool for /dev/urandom and directly injects output. Now rumors are going on that Intel works together with the NSA... and knowing that PRNGs are important for…
Luc
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Can a hard drive store clear text data that is physically impossible to retrieve?

I'm trying to study how HSM and TPM works when storing secret data in clear text. How can they achieve physical impossibility in retrieving secret data? I get the point in software, if you just have input and no outputs then it should be impossible…
einstein
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Webcam random number generator

I have a question about random number generators. I have read from a real random number generator, based on a webcam ("randcam"). My problem is, that I do not really understand how the generation of the random numbers works. Has anyone heard of…
Simon Rühle
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Crypto AG (Switzerland) - Which algorithms were used and how did the backdoors work?

Backstory Crypto AG was a company located in Switzerland that specialized in communication security. They produced a number of encryption machines (some similar to the infamous Enigma) used for secure communication. The company was secretly bought…
AleksanderCH
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AMD's implementation of RDRAND instruction

The latest AMD programmer manuals, dated June 2015, include the RDRAND instruction in the instruction set. For completeness, it lacks RDSEED. Confer, AMD64 Architecture Programmer’s Manual Volume 3: General-Purpose and System Instructions, page…
user10496
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Is it possible to utilize an AES-128 encryption hardware unit for AES-256?

There exist processors (for example ARM v8/v9 archicteture based), which cannot do AES-256 hardware based, but are equipped with AES-128 encryption hardware units. Is it possible to utilize an AES-128 encryption hardware unit in some way to speed…
0laf
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Is CPU timing jitter a usable entropy source?

In some virtualized environments, the only source of entropy available is CPU timing jitter. Can one get enough entropy from this source for practical uses? Also, is this secure against local side-channel attacks against unprivileged local…
Demi
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Different ways/algorithms for implementing AES

I have seen a couple software implementations of the Advanced Encryption Standard. They are pretty much straight forward, i.e. they are implemented exactly the same way as the AES is described. This makes an implementation of AES very easy to…
jordi88
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Usage difference between x86 RDRAND and RDSEED

Modern x86 CPUs often have the RDRAND and RDSEED instructions for hardware generation of random numbers. I just don't understand the difference between them. Intel has this document:…
Myria
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Does using modulo (%) affect quality of randomness?

I'm writing a small script that generates random non-signed decimal integers within a certain range of values. I'm using GNU od, with the following command: od /dev/hwrng --address-radix=n --read-bytes=4 --format=u4 /dev/hwrng is linked to a SoC…
user21698
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Accelerating SHA-1

I have a program where computing SHA-1 is the bottleneck. This is using OpenSSL 1.0.0e on a 2.6Ghz 16-core Opteron where I get about 325MiB/s throughput. (SHA1 here is via Andy Polyakov's x86-64 assembly implementation using SSSE3.) If I need to…
Fixee
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(EC)DSA signature without hashing, or with offloaded hash?

In (EC)DSA as per FIPS 186-4, the message to sign is first hashed. Imagine that we skip this hashing stage, instead put the message where the hash was, and constrain the size of message $h$ to the original hash's output width $N$ bits. The resulting…
fgrieu
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How to tell if a hardware RNG is rigged?

On a related note of building my own RNG, as someone suggested to use several commericial solutions how can I check if it is rigged against me? (although I am still strongly biased to a homebrew solution that is designed to be hard to subvert,…
Maxthon Chan
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Is there an algorithm or hardware that can sign/verify natural time?

PGP/GPG can used to sign text, others use public key to verify them. So one could say, that these cryptographic algorithms deal with space. Are there any algorithms that can deal with time? E.g. I sign a document at 2011-12-31 23:59:59, others can…
est
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HRNG for One Time Pad

I have just advanced to the last grade of high school (in Denmark). In this year, we all get to do one big project, where we can build/invent/create whatever we want to "solve a problem". As I study Math, IT and electronics, I would like to build…
Janman
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