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Password-Based Encryption (PBE)

The examples that we’ve given so far have used binary keys. These keys need to be stored in some fashion –  on a hard drive or floppy disk for instance. Password-based encryption (PBE) uses a password as the key. This is convenient because the security then rests with the user rather than in a physical medium. Unfortunately, password-based encryption in general isn’t as secure as algorithms with binary keys like TripleDES or Blowfish. To demonstrate this, let’s say we use Blowfish with a key size of 128 bits. That gives us a keyspace of 2128. Password-based encryption typically uses ASCII characters. An average user’s password might be 6 characters in length. If it’s entirely lowercase, there are only 266 possible keys, or roughly 228. Adding capital characters and symbols helps quite a bit, but it cannot even approach the keyspace of a good symmetric algorithm.

Symmetric Encryption

This chapter we’re going to elaborate on the subject by describing how to use the JCE to perform symmetric encryption. To begin with, we will look at how we encrypt and decrypt using symmetric encryption. Then we discuss applications for symmetric encryption, followed by some examples, which deal with the following aspects of encryption:

Basic encryption
Encryption using Blowfish
Password-based encryption
The main topics discussed in this chapter are:

The for loop

This loop is used if you know exactly how many times you want to perform a certain task. For example to print out the 2 times table you know you want to loop 10 times. The code to print out the 2 times table is listed below. It uses a for loop. Pay special attention to how the loop structure is set up.

public class TimesTable {

public static void main(String [] args) {

for(int i = 1; i<11; i++)
{
System.out.println(i + “ times 2 is “ + (i*2));

}
}
}

Compile the above code and see what happens. This code shouldn’t pose you too many problems. The first line needs some explaining. The first part of the line in brackets sets up what is called the reference variable (always an integer), the second part is what is known as the break condition (if this condition isn’t met the loop is terminated) and the last part declares how the variable is to change after each cycle of the loop (in this case when the loop gets to the bottom 1 is added to the value of i).

If we use the Mikrotik Hotspot WiFi system, all users who connect to WiFi Hotspot cannot access anything except the hotspot login page itself. After the user login then he can freely access various websites.

Then the question arises, Will the uninstalled hotspot user can access the site/web that we specify? That is the user does not need to login hotspot first to be able to access the certain web. The answer is of course Can.

Product Code Mikrotik has its own meaning. Sometimes we do not understand about what the purpose of the meaning of the name of the product code on the Mikrotik. Whereas Mikrotik Product Code is very important to know if we wanted to buy Mikrotik devices.

Sample Product Code Mikrotik RB750 , RB751Ui-2HnD, RB951G-2HnD, RB912UAG – 2HPND, RB2011UiAS-IN, CCR1009-8G-1S-1S +, CRS226-24G-2S + RM, etc.

From the example of the product code mikrotik we can know the type, type, device specifications and installation. How do I know what a product code Mikrotik? Let’s discuss together the Tutorial Mikrotik this time.