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ChaCha20 a cryptographic algo that is amazingly simple

Posted by admin |

Chacha20 is a secure, fast, and amazingly simple encryption algorithm. It's author Daniel J. Bernstein explains it well in his Salsa20 and Chacha20 design papers (which I recommend), but did not dwell on details experts already know. Filling the gap took me a while.

Read more: Link - The design of Chacha20

Feb 18, 2017 12:40

Prevent Linux raising windows, disrupting your workflow

Posted by admin |

Found an option in Compiz manager -> General options -> Focus and raise behaviour

Changed the 'Focus prevention level' from "Low" to "Normal" and it seems to have worked

Read more: Link - [SOLVED] Prevent newly opened apps to steal the focus

Feb 12, 2017 12:29

On my to-read list

Posted by admin |

Game theory credibility, could be interesting for smart contracts:

A Theory of Credibility - Credibility.pdf

Jan 22, 2017 10:47

Discourse is a very nice message board

Posted by admin |

I really like it.


Read more: Link - Discourse

Nov 20, 2016 01:16

Extract a file with the dtrx command

Posted by admin |

dtrx in Linux tries to extract any archive. It asks questions that can be a bit tricky and confuses case when doing so, but it seems to work fine.'


Untar a File in Linux/Ubuntu -

Nov 17, 2016 12:05

Starting supervisord on Ubuntu 16.04

Posted by admin |
# Make sure Supervisor comes up after a reboot.
sudo systemctl enable supervisor

# Bring Supervisor up right now.
sudo systemctl start supervisor


Read more: Link - supervisord - ubuntu server 16.04: cannot get supervisor to start automatically - Unix & Linux Stack Exchange

Nov 15, 2016 10:35

E-mail integration with chat, are there any good solutions?

Posted by admin |

I need to set up a chat for a group where some people would prefer to use their e-mail.  For these people, any mail message they send, it should immediately be posted to the chat channel. For all chats posted in the chat room, there should be options to send them out to the e-mail recepient:

  • Ever time a chat is posted
  • In digest form, every
    • hour, 3 hours, days, 3 days or every week


It turns out to be hard to find such a solution. I am currently looking at Fleep - A messenger for your teams and projects which is it's own chat, and at Email to Slack – MailClark, your team’s bot for external communicationsk for Slack. So far this is what i have found.

  • I have invited a gmail address to Fleep, but that invite does not seem to reach the fleep mobile client for that person
  • I have not found a setting in Mail Clark for chat digests

There is also something called Zapier which is more of a toolkit and does not seem to have , but so far I am seriously thinking of creating one myself, but alas I do not think I have the time.

Oct 31, 2016 04:55

How to increase the contrast of Firefox tabs

Posted by admin |

Apply this CSS somehow, for example through stylish:

.tabbrowser-tab .tab-label {     opacity: 1 !important;
  color: black !important;
  background-color: white; }

.tabbrowser-tab[pending], .alltabs-item[pending] {

    opacity: 1 !important;
  color: black !important;
  background-color: white;



If you use Stylish add this namespace line first:

@namespace url(;

I used Firefox - style of inactive or unloaded tabs - Themes and Skins for Browser - as a template.

Oct 21, 2016 04:10

Keeping the top left part of a video

Posted by admin |

ffmpeg  -i 20161019_171944.mp4 -qscale 0  -vf "crop=900:400:2000:600" cropped.mp4 0KB sq=    0B f=0/0


See more here: FFmpeg Filters Documentation

Oct 20, 2016 12:49