Import Cryptech wiki dump

1 files changed, 192 insertions, 0 deletions

diff --git a/raw-wiki-dump/GitRepositories%2Fcore%2Frng%2Ftrng b/raw-wiki-dump/GitRepositories%2Fcore%2Frng%2Ftrng
new file mode 100644
index 0000000..cda0112
--- /dev/null
+++ b/raw-wiki-dump/GitRepositories%2Fcore%2Frng%2Ftrng
@@ -0,0 +1,192 @@
+{{{
+#!htmlcomment
+
+This page is maintained automatically by a script.  Don't modify this page by hand,
+your changes will just be overwritten the next time the script runs.  Talk to your
+Friendly Neighborhood Repository Maintainer if you need to change something here.
+
+}}}
+
+{{{
+#!html
+<h1>trng</h1>
+
+<p>True Random Number Generator core implemented in Verilog.</p>
+
+<h2>Introduction</h2>
+
+<p>This repo contains the design of a True Random Number Generator (TRNG)
+for the <a href="http://cryptech.is/">Cryptech OpenHSM</a> project.</p>
+
+<h2>Design inspiration, ideas and principles</h2>
+
+<p>The TRNG <strong>MUST</strong> be a really good one. Furthermore it must be trustable
+by its users. That means it should not do wild and crazy stuff. And
+users should be able to verify that the TRNG works as expected.</p>
+
+<ul>
+<li>Follow best practice</li>
+<li>Be conservative - No big untested ideas.</li>
+<li>Support transparency - The parts should be testable.</li>
+</ul>
+
+<p>Some of our inspiration comes from:
+* The Fortuna RNG by Ferguson and Schneier as described in Cryptography
+Engineering.</p>
+
+<ul>
+<li>/dev/random in OpenBSD</li>
+</ul>
+
+<h2>System description</h2>
+
+<p>The TRNG consists of a chain with three main subsystems</p>
+
+<ul>
+<li>Entropy generation</li>
+<li>Entropy mixing</li>
+<li>Random generation</li>
+</ul>
+
+<h3>Entropy generation</h3>
+
+<p>The entropy generation subsystems consists of at least two separate entropy
+generators. Each generator collects entropy from an independent physical
+process. The entropy sources MUST be of different types. For example
+avalance noise from a reversed bias P/N junction as one source and RSSI
+LSB from a receiver.</p>
+
+<p>The reason for having multiple entropy sources is both to provide
+redundancy as well as making it harder for an attacker to affect the
+entropy collection by forcing the attacker to try and affect different
+physical processes simultaneously.</p>
+
+<p>A given entropy generator is responsible for collecting the entropy
+(possibly including A/D conversion.). The entropy generator MUST
+implement some on-line testing of the physical entropy source based on
+the entropy collected. The tests shall be described in detail here but
+will at least include tests for:</p>
+
+<ul>
+<li>No long run lengths in generated values.</li>
+<li>Variance that exceeds a given threshhold.</li>
+<li>Mean value that don't deviate from expected mean.</li>
+<li>Frequency for all possible values are within expected variance.</li>
+</ul>
+
+<p>If the tests fails over a period of generated values the entropy source
+MUST raise an error flag. And MAY also block access to the entropy it
+otherwise provides.</p>
+
+<p>There shall also be possible to read out the raw entropy collected from
+a given entropy generator. This MUST ONLY be possible in a specific
+debug mode when no random generation is allowed. Also the entropy
+provided in debug mode MUST NOT be used for later random number
+generation. </p>
+
+<p>The entropy generator SHALL perform whitening on the collected entropy
+before providing it as 32-bit values to the entropy accumulator.</p>
+
+<h3>Entropy mixing</h3>
+
+<p>The entropy mixer subsystems reads 32-bit words from the entropy
+generators to build a block of bits to be mixed.</p>
+
+<p>When 1024 bits of mixed entropy has been collected the entropy is used
+as a message block which is fed into a hash function.</p>
+
+<p>The hash function used is SHA-512 (NIST FIPS 180-4).</p>
+
+<p>The digest is then extracted and provided to the random generation as as
+a seed.</p>
+
+<h3>Random generation</h3>
+
+<p>The random generation consists of a cryptographically secure pseudo random
+number generator (CSPRNG). The CSPRNG used in the trng is the stream
+cipher ChaCha.</p>
+
+<p>ChaCha is seeded with:</p>
+
+<ul>
+<li>512 bits block</li>
+<li>256 bits key</li>
+<li>64 bits IV</li>
+<li>64 bits counter</li>
+</ul>
+
+<p>In total the seed used is: 896 bits. This requires getting two seed
+blocks of 512 bits from the mixer.</p>
+
+<p>The number of rounds used in ChaCha is conservatively
+selected. We propose that the number of rounds shall be at least 24
+rounds. Possibly 32 rounds. Given the performance in HW for ChaCha and
+the size of the keystream block, the TRNG should be able to generate
+plentiful of random values even with 32 rounds.</p>
+
+<p>The random generator shall support the ability to test its functionality
+by seeding it with a user supplied value and then generate a number of
+values in a specific debug mode. The normal access to generated random
+values MUST NOT be allowed during the debug mode. The random generator
+MUST also set an error flag during debug mode. Finally, when exiting the
+debug mode, reseeding MUST be done.</p>
+
+<p>Finally the random generator provides random numbers as 32-bit
+values. the 512 bit keystream blocks from ChaCha are divided into 16
+32-bit words and provided in sequence.</p>
+
+<h2>Implementation details</h2>
+
+<p>The core supports multpiple entropy sources as well as a CSPRNG. For
+each entropy source there are some estimators that checks that the
+sources are not broken.</p>
+
+<p>There are also an ability to extract raw entropy as well as inject test
+data into the CSPRNG to verify the functionality.</p>
+
+<p>The core will include one FPGA based entropy source but expects the
+other entropy source(s) to be connected on external ports. It is up to
+the user/system implementer to provide physical entropy souces. We will
+suggest and provide info on how to design at least one such source.</p>
+
+<p>For simulation there are simplistic fake entropy sources that can be
+found in the tb/fake_modules directory. This modules SHOULD NOT be used
+as real sources.</p>
+
+<p>For synthesis there are wrappers for the real entropy source cores to
+adapt their interfaces to what we need in the trng. These wrappers
+should not be included during simulation.</p>
+
+<h2>API</h2>
+
+<p>Normal operation:
+* Extract 32-bit random words.</p>
+
+<p>Config parameters:</p>
+
+<ul>
+<li>Number of blocks in warm-up.</li>
+<li>Number of keystream blocks before reseeding.</li>
+</ul>
+
+<p>Debug access</p>
+
+<ul>
+<li>Enable/disable entropy generator X</li>
+<li>Check health of entropy generator X</li>
+<li>Read raw entropy from entropy generator X as 32-bit word.</li>
+<li>Write 256 bit seed value as 8 32-bit words</li>
+<li>Read out one or more 512 bit keystream blocks as 32-bit words.</li>
+</ul>
+
+<h2>Status</h2>
+
+<p><strong>* (2014-09-11) *</strong></p>
+
+<p>The first version of the CSPRNG is debugged and completed. This version
+supports automatic reseeding and an output fifo.</p>
+}}}
+
+[[RepositoryIndex(format=table,glob=core/rng/trng)]]
+
+|| Clone `https://git.cryptech.is/core/rng/trng.git` ||