Krishna we use the public Internet, a specific computer network (and one which probably most readers have used), as our principle vehicle for discussing computer networking protocols. But what is the Internet? We would like to give you a one-sentence definition of the Internet, a definition that you can take home and share with your family … Read more
Now that we’ve got a bit of a feel for what the “Internet” is, let’s consider another important word is the title of this book: “protocol.” What is a protocol? What does a protocol do? How would you recognize a protocol if you met one? A Human Analogy It is probably easiest to understand the … Read more
JCA is described as a provider architecture. The primary principal in the design of the JCA has been to separate the cryptographic concepts from their algorithmic implementations. It is designed to allow different vendors to provide their own implementation of the cryptographic tools and other administrative functions. This makes a very flexible framework which willcater … Read more
The derivation of the word cryptography is from Greek and means literally secret writing . Modern cryptography is still involved in keeping data secret, but the ability to authenticate a user (and hence apply some kind of access control) is even more important. Although there are many cryptographic techniques and protocols, they mostly fall into … Read more
In the previous post We have discussed two parts of the world of Java, the development environment and the execution environment. The third part is where the world of Java meets the rest of the world, that is, the capabilities it provides for extending Java functions and integrating with applications of other types. The simplest … Read more
We have said that the JVM operates on the stream of bytecode as an interpreter. This means that it processes bytecode while the program is running and converts it to real machine code that it executes on the fly. You can think of a computer program as being like a railroad track, with the train … Read more
Once you have installed the Java 2 SDK, you can start creating Java source code and compiling it. Java is like any other high-level programming language, in that you write the source code in an English-like form. The source code then has to be converted into a form that the machine can understand before it … Read more
There are a number of different components to Java: 1. Development environment The Java 2 SDK contains the tools and executable code needed to compile and test Java programs. However, unlike a normal language, the Java 2 SDK includes object frameworks for creating graphical user interfaces, for networking and for complex I/O. Normally, in other … Read more
Where did the name GNU/Liux come from? You’ve certainly heard of Linux before, and you may have heard of the GNU Project.You may not have heard the name GNU/Linux, although you’re probably familiar with the system it refers to. Linux is named after Linus Torvalds, the creator and original author of the kernel that runs … Read more
#include <stdio.h> #include <time.h> int main() { time_t s, val = 1; struct tm* current_time; s = time(NULL); current_time = localtime(&s); printf(“%02d:%02d:%02d”, current_time->tm_hour, current_time->tm_min, current_time->tm_sec); return 0; }