# Tag Info

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I've allready replied to the question posted some days before. Montgomery multiplication is another way to perform modular multiplication in the residue system representation. The operation induced is in fact a group morphism. In GF(p), p prime, or in the multiplicative group $Z/nZ$, the transformation allows to perform modular multiplication without ...

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The confusion comes from the choice of representation. I'd a quick look to the referenced paper, where the autors use a 2-radix representation. Then you shoud initialise $e=\frac{m+15}{w}$ instead of $e=\frac{m+1}{w}$ as you use a 16 bit adder! The best is to read again the seminal paper of P.L. ...

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So, you need to do a two-part work. First, you need to make 2+ hardware sensors of an entropy of a different kind. Use the Geiger tube counter [ http://kripton2035.free.fr/geiger-repositor.html ] , avalanche noise generator [ http://www.cryogenius.com/hardware/rng/ ] and when you'll make an ARM microcontroller act as a USB device - make an AM(NOT FM) radio ...

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The general answer for rolling your own cryptographic primitives in a production system is "don't do it" because it's hard and success depends on long experience. I think the same principle applies here. If you're doing this to learn something about HWRNG systems, do it, but don't use it for anything that matters. If you're doing it to use it in a real ...

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http://www.syntax-k.de/projekte/fhreefish/ XORing the two bitstreams should be fine for mixing, by the piling-up lemma. XORing the output of that with the PRNG in the library above (or any other CSPRNG) would provide whitening. Or just send blocks of the output to Skein (or Keccak if you can find a fast implementation for AVR...) One thing to be sure ...

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BouncyCastle (for Java) has code that performs the AAD processing anywhere in the stream. It does however require modular exponentiation and additional multiplication. GCM mode officially requires the AAD to be processed before the plaintext, but as stated, there is a way around that. I've asked for an explanation here Len A||C is only required at the end ...

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I'll try to give additional explanation on algebraic number and the link with EC. Let $q=2^{163}$ the finite Field $F_q=GF(q)$, as selected by NIST has some features for doing cryptography. This field has been generated with the irreduccible pentanomial you gave in the table. To understand what the trace of the polynomial is, it corresponds to the ...

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Actually, you don't compute the trace of a polynomial per se, but of a finite-field element, which is expressed as a polynomial-like expresssion with $u$ acting as the indeterminate. ($u$, as you are probably aware, is a root of the generating polynomial $p(t)$.) Mathematically, the trace of $u$ is $$\mathrm{Tr}(u) = u + u^2 + u^4 + \cdots + u^{2^{162}}$$ ...

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