Centroid.EU Blog

(this blog is mostly encrypted - adults only)

VirgoSTAR.net to expire in ten days

August 24th, 2020

I have had this domain for a pretty long time. Usage that stands out to me are:

supercluster.virgostar.net - a vps at transip in amsterdam, good host
moon.virgostar.net - a vps in hong kong in 2014

Well the entire domain will cease in ten days now. Reminising thoughts.

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Almost forgot... UFO's

August 19th, 2020

I saw two unidentified flying objects out my kitchen window which is facing north, yesterday around 6:30PM. They did not have contrails and were very high in the sky. I concluded they may have been drones which may or may not have been painted white. Shux, dunno.

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This article is all about primes

August 19th, 2020

In the past I have written about primes, here (all prime angled triangles) and here.

I came across this video on youtube about primes making spirals. This is very interesting! It makes me wonder if this fullfils the criterea of: 1) does multiplying high primes stay on the "threads" or "arms" of low primes in the result in proportion? If so then it should be trivial factoring primes because you already know which thread it's on. And this would put RSA in risk of breaking perhaps conventionally on classical computers? You just need to know which arm/thread the resulting will be on... measure the proportion of the result and spit out the factors based on that proportion.

Whether it's really that simple I don't know. I'll keep poking at this when I have time. Thanks for the video 3Blue1Brown!

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Beacon-fire

August 15th, 2020

By default most access points emit 10 Beacon (management frames) per second. I don't know who picked this but it's concerning me because I live in a medium dense neighbourhood. When I use kismet I think it registered around 60 AP's in my vicinity. Do the simple math then that's 600 packets per second announcing the access point. In comparison the router in my parents home, which is low density living (it's a house) registers only 4 access points in its vicinity. That's only 40 packets per second for beacons or 7% of my apartment. My main concern is the radiation emitted, the second concern is the sheer waste of electricity. The smallest router I know uses up about 3W of electricity when it is announcing beacons. So do more math this is 180W of electricity being blown into the ether, and noone really makes use of it. I can power my hog computer the G5 PowerMac with that. It's a lot of aggregate power.

So what solutions do I have? For one, people could turn off their beacon signals, but then they don't get a list of AP's when they search for theirs passively. Another solution I have is that the building management tells people to turn off their radios entirely and manages the Internet. There is a few things that need to be done for that. On the wifi side the authentication has to be the enterprise authentication with username and password for each tenant. On the non wifi side the network has to be constructed in a way that the router box in every tenants home becomes a hub to ethernet cabling. So that every room has at least one or two real ethernet outlets. Some renovation is needed for that in the particular apartments that need it. So that gives each tenant ethernet which is non-wifi and wifi through the common wifi AP. There should be the possibility to create a VPN back from the AP into the tenants apartment so that they can access all their devices. I think these solutions will be a lot more healthy and don't particularily cause hardships on tenants who are not technically inclined.

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What we need

August 12th, 2020

I just came across a book on amazon. I wasn't gonna buy it but just look what's there. It is called Cyberkrank!: Wie das digitalisierte Leben unsere Gesundheit ruiniert. I hate titles like these because they are short sighted and cater to a false belief that your health is owned by the common good.

The author is saying that computers and internet are ruining lives. He is right, partially. But I believe he's just pitching an idea to make money for psychiatry. If you get people to believe they are sick, well then they must get medicated. There is a giant industry behind that.

What I'm claiming is that when the Internet came to us in 1995 roughly, that we weren't prepared. Our social structure in life did not prepare us for this. Yes I believe the Internet was disruptive to everything. But that isn't bad becuase it pointed out our flaws. What happens though is that we must adjust to the Internet for our societies. We have to make structural changes to democracy and to capitalism (the only form of system that I know).

I look at programmers and sysadmins as the bravest people on earth. Because most fall. I have seen people die having seemingly the coziest jobs on earth. It's a false picture. Programming is an activity that sucks the life out of you. You put it in a system and there it is.... your life. Everyone who does this gives up a little. And some of us get ill. But we don't feel ill, we just want to continue giving our life to the Internet. This must be addressed in societies who want "digitalization", or "cybersocieties".

Buying a cell phone is not enough. Most people don't know what to do with it. You can't program it! So it's useless. We as a society have to build our own cell phones starting at a young age is my belief. We need this digital assistant with us to follow us in our life, with the thought that "I made this!" it does not control my life. I have given this previous thought and I believe when I look at my life I was makign the best things in grade 8. Why not a cell phone? Puberty comes in the way of learning but when we have an assistant that we made ourselves from designing the chip (perhaps in grade 7) to applying it all it will prepare us for "these dumb machines". And give us a feeling that the machine will not own us, we made them. Anyhow think around that for a bit.

Systemically it is not communism but it doesn't look like capitalism or consumerism. It is something that we all forgot with advent of the first industrial revolution. I have heard stories that before industry, people were making grounds at perfecting traits in England for example. Research this. England was a forerunner to the Industrial Revolution. I'm not saying undo Industry, but are we not there already? Makerbots! 3D Printers. These things if every household has access to them change manufacturing. And put it into the peoples hands! Specialty products of course need an industrial process but what you and I use... doesn't need rocket science.

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A circle is more like a square

August 6th, 2020

No it's a rectangle! No it's two triangles!

I used squares in the past on my website to find out if someone clicked on a circle in a HTML canvas element. This works, but it's not very rounded. In fact the curves of the circle fall away and you're left with just a square. I tackled this problem yesterday once and for all, and after drawing this out I finally realised the answer.

It's not enough to measure the boundary of any dot within the area of a circle ,that is on a grid, All that is needed that you measure the distance between two points. M and P. Where M is the center of the circle and P any arbitrary point where you clicked. So then we analise, what is point P when M is (X1, Y1). P is really X1 - X2, Y1 - Y2 relative to M. And it forms a square or rectangle with one corner being M. Cut the rectangle in half you have two triangles. But not just any triangles they are right triangles. So we can apply Pythagoras theorem here because P could lie on R where line MP is the hypotenuse of the triangles (either). All we need now is to get the positive value of X1 - X2 and Y1 - Y2. Luckily computers have the abs() or fabs() function for that.

Pythagoras theorem said: A^2 + B^2 = C^2. So we can make our formuala now:

P = sqrt(pow(fabs(Y1 - Y2), 2.0) + pow(fabs(X1 - X2), 2.0));

And if P is less or equal to the Radius of the circle, then P lies in the circle.

So I have written a small C program to double check this and it works. The point M in the program is at coordinates 20, 20 and you enter x, y of P and the radius of the circle, and it will tell you if it's inside or outside of the circle.

#include 
#include 
#include 

#define CIRCLE_X        20.0
#define CIRCLE_Y        20.0

int
main(int argc, char *argv[])
{
        double x1 = CIRCLE_X, x2;
        double y1 = CIRCLE_Y, y2;

        double p, r;

        if (argc != 4) {
                fprintf(stderr, "usage: prog x-coord y-coord radius\n");
                exit(1);
        }

        r = atof(argv[3]); y2 = atof(argv[2]);
        x2 = atof(argv[1]);
        
        p = sqrt(pow(fabs(y1 - y2), 2.0) + pow(fabs(x1 - x2), 2.0));

        if (p <= r) {
                printf("With the centroid of a circle at %f, %f coordinates,"
                        " you clicked inside the circle\n", CIRCLE_X, CIRCLE_Y);
        } else {
                printf("With the centroid of a circle at %f, %f coordinates,"
                                "you did not click inside the circle\n",
                                        CIRCLE_X, CIRCLE_Y);

                exit (1);
        }

	exit (0);
}

So in any case a circle is just a square, true. No it's just a rectangle, also true, no it's two triangles, absolutely also true! I manage this on mediocre math skills, but it took a lot of thinking and visualizing it on a piece of paper that's a grid. If anyone has a better formula for this I'd love to see it! Open Mathematics!

PS: I have made a little game with javascript. If you click on the circle it will change colour, if you miss it it won't. Perfect trial for my formula.

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The 2018 Sabotage in Cornfields

August 5th, 2020

Around here, there was sabotage in corn fields around 2018. This is summed up here (german) by mainpost.de. Although they were able to get DNA data and matches, this is not a preventative from damage and someone possibly getting hurt during harvest.

So I was wondering. Would one of those consumer drones (DJI or otherwise) be able to be used to scan the field with a metal detector? Has someone done anything similar? I guess someone could program a path based on GPS for the drone to fly over the field, and someoen else gets GPS data and metal detector signal which gets digitized (on the drone either by a soundcard sampler or otherwise). I guess these sweeps for metal can be done at night too, just before a harvest. Software needs to be written for this, the idea is out there.

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Today is supposed to be hottest day of the year

July 31st, 2020

We're expecting temperatures upwards of 38C in .de. This is a lot. Currently at the Eselshoehe Wetterstation in Schweinfurt it is 16.6C so still relatively cool. But it is also 8:17AM.

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I have picked my project theme

July 31st, 2020

For the prototype fund (9th round) I have finalized what my project is going to be about.

It will be improvements for delphinusdnsd like I mentioned before, but I have a concrete picture of what I must do. I'm going to make delphinusdnsd an authoritative nameserver for replacing Microsoft DNS server. For that I need to do a few things: GSS-TSIG (RFC 3645), it comes with several depended RFC's that I also have to implement like TKEY (RFC 2930) and possibly KEY RR which comes with the SIG(0) RFC. Also I'm going to implement DNS Updates after RFC 2136 and RFC 3007 (secured), and if there is time left in the project time (6 months) I'll try to implement auto-signing updated records (DNSSEC).

This is all a big task, and there is always the hindthought that Microsoft Active Directory won't allow this. I have found a document from Bluecat Networks that they can do this (on a BIND9 basis). So this will be my outline that I will be working/striving towards. Wish me luck, I'm applying tomorrow, most likely.

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Removed CVSweb from my servers

July 28th, 2020

The day had to come, I'm thinking. If you were browsing my CVS repo on my site I have replaced it with a GOT repo. I will reinstitute most software on GOT when I can. CVSweb didn't do it for me anymore when it stopped displaying commits to a branch. I will continue using the CVS without a web interface until the delphinusdnsd 1.5.0 release at which point I'll likely switch completely to got/git. Sorry for any inconvenience if you were going through my repo, just at this time when I removed it.

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