So you want to know about Bitcoin…

--Originally published at Computer and Information Security

Hey reader! I’m glad you keep digging at my posts, that’s nice of you. This time I will talk about Bitcoin.

From the official page of Bitcoin we can find that this type of coin is:

Bitcoin uses peer-to-peer technology to operate with no central authority or banks; managing transactions and the issuing of bitcoins is carried out collectively by the network. Bitcoin is open-source; its design is public, nobody owns or controls Bitcoin and everyone can take part. Through many of its unique properties, Bitcoin allows exciting uses that could not be covered by any previous payment system.

As you can see, the P2P technology that they talk about is something called blockchain, which you can read about in my previous post. In the big picture, Bitcoin is nothing than just a program that uses hash tables and is about transactions made in the web through a certain amount of time, and the one that solves the math problem first is the one that can charge a small amount of the bitcoin value.

That’s it, I tryied to explain to you in simple words what this is, but as I know that you are more graphical than just words, I will leave a video of how to create your own Cryptocurrency in JavaScript:

Part 1

Part 2


Blockchain – As you saw it on TV! Actually in the web with Bitcoin

--Originally published at Computer and Information Security

Sup, reader! I feel like a little rusty talking to you since I haven’t uploaded in a while and that’s something I want to change today.

Today’s topic is about blockchain, you will be asking yourself, wt… is blockchain, well, this is nothing that how Bitcoin works, I mean, this is not a post about Bitcoins if that’s what you think you will learn here, for that I recommend you to look it up in my later blog post, where I talk about some cryptocurrency. But, for now I will explain as how I understood from a video that a person made online. I will tell you how I interpret it, but of course I will leave the video down somewhere here, for you to understand the basic concepts about how something like Bitcoins work.

First we have an ecosystem of computers connected in the whole world, through the internet, imagine like a bunch of computers connected with a lan, something, like a mesh. For example this image:

Resultado de imagen para mesh network

Here you can see a lot of devices connected, this is known as a descentralized and distrubuted, distributed because, each computer or device has a copy of each transaction and doesn’t depend on a third party, like how banks works, where you need a banc account which is managed by a banker and in order to reflect when you make a transaction, it needs to be aproved by this banker. So, in blockchain, what is trying to do, is to remove those third party entities, so that, each one of us can have a very transparent and out of corruption system. And, descentralized because, the transcations are reflected in each device connected to this system.

The basic component of the blockchain is  a layer, which is something like you see in the

Continue reading "Blockchain – As you saw it on TV! Actually in the web with Bitcoin"

Information security

--Originally published at TC2027 – Titel der Website


Information security refers to the characteristics of information processing and storage (technical or non-technical) systems that meet the confidentiality, availability and integrity protection goals.

Security meets threats, avoiding economic damage and minimizing risks.

In practice, information security is based on IT security management under the international ISO / IEC 27000 series. In German-speaking countries, a procedure based on IT-Grundschutz is widespread.

In the area of evaluation and certification of IT products and systems, the standard ISO / IEC 15408 (Common Criteria) is frequently used.

Formatting of a Windows Computer

--Originally published at TC2027 – Titel der Website

Thats a blog post for two courses of Ken. TC1017 & TC 2027.

The reason why i took this topic is first of all, that Ken talked a lot in this semester about reason why we should Format a computer. Reasons are, that a student clicks a lot of times not serious links or just download a lot of trash to the computer. The result is most of the time a super slow computer. A computer which worked 1000 times slower than the first day of using.


An other reason is a personal reason. I guess i am one of the students, which did a lot of mistakes with clicking links and download trash. So why i post this is, i just Format one time in my life a computer by my own. I just want to do that again. To learn how it works and to rescue my lovely Surface 4 ?


To the operative work:

It is super easy to format a Windows computer nowadays.

The first step is to safe all your Datas, which you not want to lose. But important is, to realize that maybe movies, music or other stuff from strange websites could be the reason why a computer is not running like it should. So think twice if you also want to safe all the trash!

The reason for the first step is, that the computer will be empty after the process for Formatting.

Now the steps

  1. Simultaneously press the [Windows] and [R] keys to open the Run command.
  2. Enter „diskmgmt.msc“ here and confirm with „OK“. Subsequently, the disk management opens.
  3. Select the desired hard disk from the list and click on it with the right mouse button.
  4. Select the option „Format“ and confirm the process via the „OK“ button.
  5. Then the hard
    Continue reading "Formatting of a Windows Computer"

Hacking adventures (Story 1)

--Originally published at Computer and Information Security

Oh! Hi reader, I’m really impressed that you keep coming to read what I have to tell to the world hehehe. This time I will tell a little story as I promised on my first post.

It all begins when I was in highschool, the really young and naive Cande, the little geek who was starting to learn how to set-up a web site server. One day, Cande got an idea, he thought: “What if I set-up a CMS in my brother’s server to learn how a server works and how to manage files in there, but also to share some of my thoughts to the world?” Well that sounds really cool isn’t it? You might think, oh wow this guy has some initiative, but in that time, he also had a lot of naivety. Let me explain to you why:

  1. He downloaded a wordpress template from those sketchy sites that offer everything free to download, he thought: “Oh, I’m going to search a cool wordpress template and modify it to make it look nicer!”
  2. After he downloaded it, he made all the modifications in his machine: “Where is the style folder of this template? Oh I found it!” -2 hours later-, “Cool, I finished my master piece”.
  3. Then, he opted to upload all of his downloaded files to the server: “Ok, now I just need to upload my root folder to the server.
  4. Once his site was uploaded, he went to check it, to see if everything was ok: “Everyhting is up and running, now, I just have to enter my site address and check it out, I’m really excited” -1 minute later-, “Hell yeah, my site rocks, looks pretty cool, I’m gonna start publishing my first post”.
  5. Days passed and each day Cande logged in
    Continue reading "Hacking adventures (Story 1)"

How to prevent e-mail viruses?

--Originally published at Computer and Information Security

Hello reader, today’s topic is about e-mail viruses. We all have been in the wrong position where you download a file or something sent through the mail, and never check if the sender is a real one or check if the file has a proper extension depending on the type of file you were supposed to receive (For example: a text file should end in .txt a pdf in .pdf, etc.) but many people doesn’t check about that and just double click the downloaded file, which ends in another zombie computer infected with viruses like trojans or worms, which keep reproducing and propagating through the home or any network to other devices.

So, in order to at least prevent that you get infected with any virus, you first should evaluate the mail sender, check if the mail that is sending you a mail is valid and track it. So, I recommend you to use this tool, in order to check an e-mail:

It gives you metadata (important and detailed information) of the e-mail, that tells you from where it was sent, servers, validation of the records and a score of reputation.

For example, here is the score it gave me of some mails and data from the server of the fake account:



After you check a mail validation and the score is almost trustworthy, you should Google the e-mail addres to re-validate.

And one last thing, never, ever, click links inside a mail. If your guts tell you that it might be a phising or a scam, it is probably one.

See you on the next post!!!