Semantic Layer and Propagation Layer in Blockchain.

Layers of Blockchain: Application Layer & Execution Layer

 Layers of Blockchain: Application Layer

 Layers of Blockchain: Execution Layer

Let's Discuss History of Blockchain From 1991 to 2023. Difference between Centralized vs Decentralized System?

 History of Blockchain:

Q. Differentiate between Centralized Vs Decentralized System.?

How to convert E R Diagrams into Tables : Explained all Rules in detail with example.

Converting E R Diagrams into Tables:

Explained in details with all Rules, where and how to apply those rules at the time of E R diagram conversion into tables.

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Explain Merkle Tree? How Merkle Tree plays an important role in block structure of Blockchain?

Digital Signature Algorithm: explanation with block diagram.

 Digital Signature Algorithm:

As we know, DSA use public key cryptography that is Asymmetric key cryptography algorithm for encryption.

1. So, both sender and receiver generate the public key and private key.

2. To generate digital signature.

    2.1 Take a plain text pass it to SHA256 hash function it will generate digest of 256 bit.

    2.2 When we combine this 256-bit digest with private key of sender we will get a digital signature.

    2.3 Take a plain text encrypt it with receiver's public key we will get encrypted message.

3. Once we will get digital signature and encrypted message from sender side then send it to the network

    on receiver side.

4. on receiver side we have to unlock this with the help of receiver public key.

    4.1 Encrypted message we have to decrypt with the help of private key of receiver. 

    4.2 We will get a plain text, send that plain text once again to the SHA-256 hash function.

    4.3 We will get digest d2 from this of 256 bits.

    4.4 After unlocking with the public key of receiver we will get two things encrypted message and 

          digest d1.

    4.5 Compare digest d1 with digest d2 if both finds equal that means we will receive untampered or 

          original message as it is. if digest d1 is not equal to digest d2 that means we are not getting 

          original message.

 How does SHA- 256 algorithm works?

A Step by step detailed explanation of SHA-256 algorithm with example.

Step 1: Pre Processing:

Exercise for you:

How many bits you will pad for input message length of 2348 bits?

Solution:

Step 2: Initialize Hash Values (a, b, c, d, e, f)

Step 3: Initialize round constants K. (K0.. K63)

Step 4: Chunk Loop (0 .. 63)

Step 5: Create message schedule(W):

Step 6: Compression

Step 7: Modify final values

Step 8: Concatenate final hash