Cryptography – Goals and Methods

--Originally published at TC2027 – Titel der Website

Cryptography is a word from the oldgreek language. „κρυπτός kryptós“ means hidden or secret and „γράφεινgráphein“ means writing.

Cryptography is originally the science of encryption of information. In simple we can say that cryptography is the encryption of data or messages of any kind.

 

Goals

Modern cryptography has four main objects for protecting data, messages and / or transmission channels:

  1. Confidentiality: It is to ensure that only the person who receives the message can read and read it.
  2. Integrity: The receiver should be able to determine whether the data or the message was changed after its creation.
  3. Authenticity: sender or originator of data or messages shall be identifiable or the recipient shall be able to verify who is the author.
  4. Liability: The author shall not be able to deny that he is also the author of the data / message.

It should be noted, that that cryptographic methods do not necessarily always fulfill all four objectives. It always depends on the method, which target is followed. So, you have to estimate which method is implemented.

Methods of Cryptography

Cryptography is divided into classical and modern procedures.

The classical procedures:

As long as no electronic computers were used for cryptography, encryption was always replaced by complete letters or groups of letters. Such procedures are now obsolete and unsafe.

  • Transposition: The letters of the message are simply arranged differently. Example: Garden fence method or Skytale.
  • Substitution: The letters of the message are replaced by a different letter or symbol. Monoalphabetic substitution and Polyalphabetic substitution. Examples include Caesar encryption and Vigenère encryption.

 

The modern procedures:

Malware – what is it and how can you protect yourself against it?

--Originally published at TC2027 – Titel der Website

What is a Malware?

Malware (short form of „Malicious Software“) is any type of malicious or malicious software which is to be accessed secretly or without the knowledge of the user on a device.

Malware is a collection of programs. There are many types of malware – for example, viruses, trojans, rootkits or spyware. All work different and have different tasks. But you have a common goal: to harm you.

 

How to get capture a malware?

Malware can be everywhere, whether it is surfing the web, opening a download or attaching an e-mail attachment or connecting a USB stick. Only rarely do you ever get infected with your PC – unless your anti-virus software has averted the risk.

Even if threats are everywhere, you do not have to pull the network cable and set the surfing. With the necessary software and a critical view on websites, downloads and e-mails, you do not need to worry.

 

How to protect against Malware?

  • Anti-virus software: The protection against viruses is an anti-virus program, which is always updated. You are also protected against the latest viruses. Good and free software is available from Avira, Avast, AVG, Comodo and BitDefender.

 

  • Firewall: The firewall is already activated by default in Windows. It controls all incoming and outgoing connections and locks them in case of problems.

 

  • Updates: To keep your system and your programs safe, you should always install the latest updates for Windows and use only the latest versions of your programs.

 

What Typs of Malware are there?

Virus: A virus consists of only one file containing a malicious code. The infects the virus into a program, makes it mostly useless and then attempts to spread further.

Trojans: The Trojan is also known as a trojan horse, because the

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Deal better with passwords

--Originally published at TC2027 – Titel der Website

Dear students and friends,

 

in my Blog post i am going to Talk about „how to deal with passwords on the Internet“.

We talked about this issue in the course of Ken „Computer and Information Security“. The point is, that the average Internet user have just 5 or less passwords for every page where they logged in.

This is a big problem when you have for example the same password for Paypal and Amazon. So problem is, if someone hacks one of this accounts you may have a big financial problem.

This could lead to a financial ruin.

 

But why do just a few people think about such things when this actually happens all the time?

This is due to the human being. Humans tends to learn things only when something bad happens to himself.

 

To be honest, I thought sometimes, that i really use always the same passwords and i was worried. But i did nothing. Only after this lecture where we talked about stuff like this I have dealt with it.

 

To ensure a safer stay on the Internet, I have installed the AddOn Lastpass for my browser.

LastPass is a freemiumpassword management service that stores encrypted passwords in private accounts. LastPass is standard with a web interface, but also includes plugins for many web browsers and apps for many smartphones.[1] It also includes support for bookmarklets.[2]

https://en.wikipedia.org/wiki/LastPass

 

Specials of Lastpass:

  • safes all your passwords and Email adresses
  • put the internet sites in categories
  • creates safe passwords for you (if you want)
  • can make a safety check of all your passwords

 

The most important thing with LastPass is, that you need a Master-Password. This should be something super long. It is the best to use a completely

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