Types of block chain

 There are four different types of blockchains. They are as follows:

Private Blockchain Networks

Private blockchains operate on closed networks, and tend to work well for private businesses and organizations. Companies can use private blockchains to customize their accessibility and authorization preferences, parameters to the network, and other important security options. Only one authority manages a private blockchain network.

Public Blockchain Networks

Bitcoin and other cryptocurrencies originated from public blockchains, which also played a role in popularizing distributed ledger technology (DLT). Public blockchains also help to eliminate certain challenges and issues, such as security flaws and centralization. With DLT, data is distributed across a peer-to-peer network, rather than being stored in a single location. A consensus algorithm is used for verifying information authenticity; proof of stake (PoS) and proof of work (PoW) are two frequently used consensus methods. 

Permissioned Blockchain Networks

Also sometimes known as hybrid blockchains, permissioned blockchain networks are private blockchains that allow special access for authorized individuals. Organizations typically set up these types of blockchains to get the best of both worlds, and it enables better structure when assigning who can participate in the network and in what transactions.

Consortium Blockchains

Similar to permissioned blockchains,  consortium blockchains have both public and private components, except multiple organizations will manage a single consortium blockchain network. Although these types of blockchains can initially be more complex to set up, once they are running, they can offer better security. Additionally, consortium blockchains are optimal for collaboration with multiple organizations.

The Process of Transaction

One of Blockchain technology’s cardinal features is the way it confirms and authorizes transactions. For example, if two individuals wish to perform a transaction with a private and public key, respectively, the first person party would attach the transaction information to the public key of the second party. This total information is gathered together into a block.

The block contains a digital signature, a timestamp, and other important, relevant information. It should be noted that the block doesn’t include the identities of the individuals involved in the transaction. This block is then transmitted across all of the network's nodes, and when the right individual uses his private key and matches it with the block, the transaction gets completed successfully.

In addition to conducting financial transactions, the Blockchain can also hold transactional details of properties, vehicles, etc.

Here’s a use case that illustrates how Blockchain works:

• Hash Encryptions

  blockchain technology uses hashing and encryption to secure the data, relying mainly on the SHA256 algorithm to secure the information. The address of the sender (public key), the receiver’s address, the 
• . The encrypted information, called hash encryption, is transmitted across the world and added to the blockchain after verification. The SHA256 algorithm makes it almost impossible to hack the hash encryption, which in turn simplifies the sender and receiver’s authentication.

• Proof of Work

  In a Blockchain, each block consists of 4 main headers.
  • Previous Hash: This hash address locates the previous block.
  • Transaction Details: Details of all the transactions that need to occur.
  • Nonce: An arbitrary number given in cryptography to differentiate the block’s hash address.
  • Hash Address of the Block: All of the above (i.e., preceding hash, transaction details, and nonce) are transmitted through a hashing algorithm. This gives an output containing a 256-bit, 64 character length value, which is called the unique ‘hash address.’ Consequently, it is referred to as the hash of the block.
  • Numerous people around the world try to figure out the right hash value to meet a pre-determined condition using computational algorithms. The transaction completes when the predetermined condition is met. To put it more plainly, Blockchain miners attempt to solve a mathematical puzzle, which is referred to as a proof of work problem. Whoever solves it first gets a reward.

  • Mining

    In Blockchain technology, the process of adding transactional details to the present digital/public ledger is called ‘mining.’ Though the term is associated with Bitcoin, it is used to refer to other Blockchain technologies as well. Mining involves generating the hash of a block transaction, which is tough to forge, thereby ensuring the safety of the entire Blockchain without needing a central system

Unlocking block chain: how does block chain work

 recent years, you may have noticed many businesses around the world integrating Blockchain technology. But how exactly does Blockchain technology work? Is this a significant change or a simple addition? The advancements of Blockchain are still young and have the potential to be revolutionary in the future; so, let’s begin demystifying this technology.

Blockchain is a combination of three leading technologies:

1. Cryptographic keys
2. A peer-to-peer network containing a shared ledger
3. A means of computing, to store the transactions and records of the network

Cryptography keys consist of two keys – Private key and Public key. These keys help in performing successful transactions between two parties. Each individual has these two keys, which they use to produce a secure digital identity reference. This secured identity is the most important aspect of Blockchain technology. In the world of cryptocurrency, this identity is referred to as ‘digital signature’ and is used for authorizing and controlling transactions.

The digital signature is merged with the peer-to-peer network; a large number of individuals who act as authorities use the digital signature in order to reach a consensus on transactions, among other issues. When they authorize a deal, it is certified by a mathematical verification, which results in a successful secured transaction between the two network-connected parties. So to sum it up, Blockchain users employ cryptography keys to perform different types of digital interactions over the peer-to-peer network

Block chain popularity secret

 Suppose you are transferring money to your family or friends from your bank account. You would log in to online banking and transfer the amount to the other person using their account number. When the transaction is done, your bank updates the transaction records. It seems simple enough, right? There is a potential issue which most of us neglect.

These types of transactions can be tampered with very quickly. People who are familiar with this truth are often wary of using these types of transactions, hence the evolution of third-party payment applications in recent years.  But this vulnerability is essentially why Blockchain technology was created.

Technologically, Blockchain is a digital ledger that is gaining a lot of attention and traction recently. But why has it become so popular? Well, let’s dig into it to fathom the whole concept.

Record keeping of data and transactions are a crucial part of the business. Often, this information is handled in house or passed through a third party like brokers, bankers, or lawyers increasing time, cost, or both on the business. Fortunately, Blockchain avoids this long process and facilitates the faster movement of the transaction, thereby saving both time and money.

Most people assume Blockchain and Bitcoin can be used interchangeably, but in reality, that’s not the case. Blockchain is the technology capable of supporting various applications related to multiple industries like finance, supply chain, manufacturing, etc., but Bitcoin is a currency that relies on Blockchain technology to be secure.

Blockchain is an emerging technology with many advantages in an increasingly digital world:

• Highly Secure

  It uses a digital signature feature to conduct fraud-free transactions making it impossible to corrupt or change the data of an individual by the other users without a specific digital signature.

• Decentralized System

  Conventionally, you need the approval of regulatory authorities like a government or bank for transactions; however, with Blockchain, transactions are done with the mutual consensus of users resulting in smoother, safer, and faster transactions.

• Automation Capability

  It is programmable and can generate systematic actions, events, and payments automatically when the criteria of the trigger are met

Block chain technology

 over the past few years, you have consistently heard the term ‘blockchain technology,’ probably regarding cryptocurrencies, like Bitcoin. In fact, you may be asking yourself, “what is blockchain technology?” It seems like blockchain is a platitude but in a hypothetical sense, as there is no real meaning that the layman can understand easily. It is imperative to answer “what is blockchain technology, “including the technology that is used, how it works, and how it’s becoming vital in the digital world.

As blockchain continues to grow and become more user-friendly, the onus is on you to learn this evolving technology to prepare for the future. If you are new to blockchain, then this is the right platform to gain solid foundational knowledge. In this article, you learn how to answer the question, “what is blockchain technology?” You’ll also learn how blockchain works, why it’s important, and how you can use this field to advance your career.

What Is Blockchain Technology?

Blockchain technology is a structure that stores transactional records, also known as the block, of the public in several databases, known as the “chain,” in a network connected through peer-to-peer nodes. Typically, this storage is referred to as a ‘digital ledger.’

Every transaction in this ledger is authorized by the digital signature of the owner, which authenticates the transaction and safeguards it from tampering. Hence, the information the digital ledger contains is highly secure.

In simpler words, the digital ledger is like a Google spreadsheet shared among numerous computers in a network, in which, the transactional records are stored based on actual purchases. The fascinating angle is that anybody can see the data, but they can’t corrupt it

ISSB preparation tips

 overview about what all is there

All the tests are given on a website named Hawinfo as well
The first thing which you will be doing there is a lot of form filling. try to write the same things in all the forms because you will be asked to fill more than 2 forms there.

Then comes the address by commandent ISSB. The very 1st day there are intelligence tests. You can find some exercise which are relevant to the tests here
After the intelligence test is done you will be doing mechanical aptitude test which includes some easy questions from physics.
The next things is psychologists tests which are the main crux of ISSB. this includes tests such as
Sentence completion English. You will be given two papers which contains 26 incomplete sentences in English and you need to complete them in 6 minutes. You can find some examples here
Next is the sentence completion in urdu. Here you have the same thing 2 papers of 26 incomplete sentences and the time is also same. find some useful examples of the test here
then you will be shown 2 pictures on a projector now you have to write stories on these pictures. Make sure you right a positive one. Some example stories are solved here read them
Next comes word association test now you will be shown some 100 words and each word will be displayed for 10 seconds you have to make sentence on it during that time....See some useful exercises here
the last test in the psychologist is pointer stories writing ....An incomplete story is given and you need to solve it...See the exercises here
There are 2 interviews in ISSB one by Deputy, and one by psychologist. Psychologist interview is based upon you psychological tests for Deputy and psychologists Interview watch the questions here
then you have many physical tasks which are

CSS versus ISSB : What do you want to do?

 If you want to join armed forces of Pakistan then you'll have to pass ISSB along with other tests. However if you want to serve as civil servant then go for CSS exams.

Comparing css officer with army officer, Well CSP officer right from the start have powers as CSP has to deal with public affairs mostly. So in public affairs matters CSP is powerfull. As for example ASP is more powerfull then Major of Army.

But after promotions of army officer to higher rank for example to Brig. OR Maj .Gen and so on. Powers of these ranked officers are aslo very much, as we all know we are enlslaved of our own army. Army is more powerfull then civil beurecracy.

But if you look in the perspective of direct powers then CSP has more powers than Army officals.

Army is indepennt organization while many CSP work under ministries. so politics can influence csp officer but not to an army offical.

Scholarship : how to get scholarships

 Dear Aspirants: I am sure you read Waqar bhai's post about Italian Scholarship Rejection and I have personally noticed that Pakistani Students are not represented in such a majority in US universities either. While I pursued my Undergraduate Degree in the US and now doing my Ph.D. there, I have noticed this dilemma, and tons of mentors have brought it to your attention as well.

T have other mentors that Scholarships are Competitive not because there are many students but also because you are competing against international talent too.

If you can not make the effort to open the link and read the requirements for the program then I can not comprehend how do you comprehend that you can sustain and do well abroad

If you are so uncertain about giving IELTS/TOEFL, constructing SOP, creating your CV, Giving the GRE, Making a Research Proposal; that we hope that someone just gives us all the information and we do not have to do much then we will continue to lack and be underrepresented

We need to think this fact that we must quit running after acceptance letters. I have seen students just mindlessly asking for an acceptance letter from professors that have research not even close to what they want to pursue.

Students continue to send the same email to every professor and then ask, WHY ARE WE REJECTED?

We do not take time to read the profile of the professor, read their research, read some of their papers and try to understand what are their active projects because we claim that "IT WASTES SO MUCH TIME".

If you think that doing hard work is waste of time than let me tell you that trying to find the shortcut is the biggest waste of your time because to achieve success NO SHORTCUT EXISTS

SO HOW TO RECTIFY THIS PROBLEM?

Try to spend some time reading the requirements of the program. Do not blindly apply as soon as you see the word "FULLY FUNDED"

Stop chasing acceptance letters and try to find a perfect match with you and the lab you want to do research in. 

Please start working on your profile by constructing a compelling CV, SOP and other material ahead of the application deadline. If you start gathering your documents days before your deadline than you will not be able to carefully make sure that you have fulfilled all the requirements

Do apply to multiple programs on the same SOP, IT IS NOT GOING TO WORK IN YOUR FAVOR

If you are applying to US, know that GRE is not some sort of a foreign BEAST! The test is designed for humans by humans and not for robots. We all take these exams and we all can do well, if we put the same dedication as we put in things that are of interest to us

If you can spend hours browsing the internet then you should also be able to spend hours trying to find scholarship opportunities

PLEASE understand the importance of RESEARCH! It is rather impossible to get into PhD if you have no research experience. Instead of sitting and blaming your country, your institutions, and other people, start taking responsibility of your actions!

If you did not have the opportunity to do research, you must do an internship or a job relevant to your field before you apply for PhD!

Do not assume someone knows that you know the skills. If you do not mention that in your CV, I can not know that you have Research Skills

MORAL OF THE STORY: Let us stop blaming others for our failure and take responsibility of our actions! Work hard! There is no success if you can not take the time to work hard! Failure should not disappoint you but let it teach you!he Biggest Problem is: TRYING TO FIND A SHORT CUT