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smuellerDD
jitterentropy-library
C2019–2022
smuellerDD / jitterentropy-library

jitterentropy-library

Jitterentropy Library

Libraries & SDKs
Explore on GitHubRead Hacker News discussions
3Distinct people
3Mentions
0Explicit recommenders
160GitHub stars
REPOSITORY AT A GLANCE

What to know before exploring

What it is

Jitterentropy Library

GitHub

Where it is used

No documented product use has been verified yet.

What people are saying

No recommendation phrase was found in the indexed comments.

No classified warning is attached to this page. Read the discussions before treating silence as approval.

Also in these discussions

No other repository is repeatedly linked in the same discussions.

This week on Hacker News

Nov 7–Nov 14 UTC · Direct repository links and separately labeled related project stories. Indexed through 11/14/2026, 3:56:07 PM UTC.

No direct repository links were found in the indexed HN discussions over the past seven days. Older discussions are available below.

Mentions over time

HN mentions by month3 dated mentions

Observed mentions: 2019-10-04 06:33:50 UTC to 2022-02-17 22:35:42 UTC.

0122019-10-01 00:00:00 UTC to 2019-11-01 00:00:00 UTC (exclusive): 2 mentions; 0 submissions, 2 commentsOct 20192019-11-01 00:00:00 UTC to 2019-12-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2019-12-01 00:00:00 UTC to 2020-01-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2020-01-01 00:00:00 UTC to 2020-02-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2020-02-01 00:00:00 UTC to 2020-03-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2020-03-01 00:00:00 UTC to 2020-04-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2020-04-01 00:00:00 UTC to 2020-05-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2020-05-01 00:00:00 UTC to 2020-06-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2020-06-01 00:00:00 UTC to 2020-07-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2020-07-01 00:00:00 UTC to 2020-08-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2020-08-01 00:00:00 UTC to 2020-09-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2020-09-01 00:00:00 UTC to 2020-10-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2020-10-01 00:00:00 UTC to 2020-11-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2020-11-01 00:00:00 UTC to 2020-12-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2020-12-01 00:00:00 UTC to 2021-01-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 commentsDec 20202021-01-01 00:00:00 UTC to 2021-02-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2021-02-01 00:00:00 UTC to 2021-03-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2021-03-01 00:00:00 UTC to 2021-04-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2021-04-01 00:00:00 UTC to 2021-05-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2021-05-01 00:00:00 UTC to 2021-06-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2021-06-01 00:00:00 UTC to 2021-07-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2021-07-01 00:00:00 UTC to 2021-08-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2021-08-01 00:00:00 UTC to 2021-09-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2021-09-01 00:00:00 UTC to 2021-10-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2021-10-01 00:00:00 UTC to 2021-11-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2021-11-01 00:00:00 UTC to 2021-12-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2021-12-01 00:00:00 UTC to 2022-01-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2022-01-01 00:00:00 UTC to 2022-02-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2022-02-01 00:00:00 UTC to 2022-03-01 00:00:00 UTC (exclusive): 1 mentions; 0 submissions, 1 commentsFeb 2022

Counts come from the repository’s dated source evidence. Index cutoff: 2026-11-02 08:16:59 UTC.

View mention counts and date ranges
UTC ranges include their start and exclude their end. Select a period to filter the source evidence.
PeriodStart (UTC)End (exclusive, UTC)MentionsSubmissionsComments
Oct 20192019-10-01 00:00:00 UTC2019-11-01 00:00:00 UTC202
Nov 20192019-11-01 00:00:00 UTC2019-12-01 00:00:00 UTC000
Dec 20192019-12-01 00:00:00 UTC2020-01-01 00:00:00 UTC000
Jan 20202020-01-01 00:00:00 UTC2020-02-01 00:00:00 UTC000
Feb 20202020-02-01 00:00:00 UTC2020-03-01 00:00:00 UTC000
Mar 20202020-03-01 00:00:00 UTC2020-04-01 00:00:00 UTC000
Apr 20202020-04-01 00:00:00 UTC2020-05-01 00:00:00 UTC000
May 20202020-05-01 00:00:00 UTC2020-06-01 00:00:00 UTC000
Jun 20202020-06-01 00:00:00 UTC2020-07-01 00:00:00 UTC000
Jul 20202020-07-01 00:00:00 UTC2020-08-01 00:00:00 UTC000
Aug 20202020-08-01 00:00:00 UTC2020-09-01 00:00:00 UTC000
Sep 20202020-09-01 00:00:00 UTC2020-10-01 00:00:00 UTC000
Oct 20202020-10-01 00:00:00 UTC2020-11-01 00:00:00 UTC000
Nov 20202020-11-01 00:00:00 UTC2020-12-01 00:00:00 UTC000
Dec 20202020-12-01 00:00:00 UTC2021-01-01 00:00:00 UTC000
Jan 20212021-01-01 00:00:00 UTC2021-02-01 00:00:00 UTC000
Feb 20212021-02-01 00:00:00 UTC2021-03-01 00:00:00 UTC000
Mar 20212021-03-01 00:00:00 UTC2021-04-01 00:00:00 UTC000
Apr 20212021-04-01 00:00:00 UTC2021-05-01 00:00:00 UTC000
May 20212021-05-01 00:00:00 UTC2021-06-01 00:00:00 UTC000
Jun 20212021-06-01 00:00:00 UTC2021-07-01 00:00:00 UTC000
Jul 20212021-07-01 00:00:00 UTC2021-08-01 00:00:00 UTC000
Aug 20212021-08-01 00:00:00 UTC2021-09-01 00:00:00 UTC000
Sep 20212021-09-01 00:00:00 UTC2021-10-01 00:00:00 UTC000
Oct 20212021-10-01 00:00:00 UTC2021-11-01 00:00:00 UTC000
Nov 20212021-11-01 00:00:00 UTC2021-12-01 00:00:00 UTC000
Dec 20212021-12-01 00:00:00 UTC2022-01-01 00:00:00 UTC000
Jan 20222022-01-01 00:00:00 UTC2022-02-01 00:00:00 UTC000
Feb 20222022-02-01 00:00:00 UTC2022-03-01 00:00:00 UTC101

What Hacker News says

3 sources
loeg·Oct 4, 2019
I'll pass on most of this rant, just want to correct this misunderstanding: > That one? https://fuchsia.dev/fuchsia-src/zircon/jitterentropy/config-.... > It's one of the first links I found, I hope it is obsolete: they say the internal state of Jitterentropy is puny 64 bits number You skimmed too quickly and came to a judgement based on a misreading or misunderstanding of the concept. Obviously 64 bits is not sufficient. The idea of the jitter entropy mechanism is that most modern CPUs have super high resolution clock or cycle counters available (even embedded boards), and instruction execution speed has mild variance. You run a series of trials, each of which produces one or more bits of output (classically: 1). You run as many as you want, producing an infinite stream of weak entropy, until you have collected a satisfactory number of
Read the rest
output bits. Trials can be run relatively quickly (many nanoseconds or a handful of milliseconds per trial). For each trial, you perform some minimal workload intended to exacerbate CPU runtime variance (this might be where you saw "64 bits"), and extract some number of output bits (maybe 1) from one or more of: the low bits of the cyclecounter, nanosecond clock, or something similar of that nature. Caveat: jitter is an even weaker entropy source than most non-HWRNG sources typically consumed by entropy gatherers. Your motto of "just 256 bits" assumes total independence and 8 bits per byte of entropy. It isn't met by most real-world entropy sources on server systems (expect 4-5 bits/byte) and especially not by jitter entropy. Empirically, jitter seems to come closer to 1 bit per byte minimum in SP800-90B evaluations on the raw output — it's a pretty weak entropy source. Anyway: feel free to read more about the concept at any of the sources. The Fuschia writeup you linked is a good one if you read it more closely; there's also: * From the original (2013) proponent, Stephan Mueller: description: http://www.chronox.de/jent.html and sources: https://github.com/smuellerDD/jitterentropy-library * LWN's 2015 writeup of the concept as a Linux entropy source: https://lwn.net/Articles/642166/ * And this is all suddenly topical due to the latest nonsense from Linus (TFA, 2019), who still does not understand CSPRNGs. Anyway, Linus wrote and merged a version of jitter entropy quite recently: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/lin... This is a relatively happy outcome in that Linus didn't just break the ABI to be completely insecure by default.
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