Steemit Crypto Academy, Season 3: Week 2 || Hash and Cryptography.// By:@zeeshanakram//

Hello steemians how are you all of you. I hope you will be fine. Alhamdulilah I am also fine with the grace of Allah Almighty. I am very thankful to Professor: @pelon53 for this informative lecture about hash and cryptography.

Question:

Explain what does the resistance to collision mean? And what does resistance to preimage mean?

Ans:

I read the lecture thoroughly and according to me the whole lecture is about has function so first of all we start discuss about has function. That what is has function?

Define about hash function?

Basically hash is a function that change the block according to mathematically operation containing more or less information summarized in a hash. This function applies to incoming messages. The incoming message is converted to a non-winning number. The length of these numbers is fixed. This means that the input length is not fixed but the output length is fixed. Resistance battle and resistance before resistance are the features of hash performance. The hash function is an important math A function that plays a key role in general key intelligence. The hash function helps to store passwords in blockchains. These hash algorithms are used to validate and integrate different types of inputs, to write new transactions in the blockchain through the extraction process. This hash is very important in blockchain because it is mostly used to prevent the placement of long and simple texts as a password in blockchain.

Functions such as inputting words regardless of file size and converting them to a hash as a fixed-length output, such as checking security, messages or data integrity, verifying information with the importance of encryption help the hash function. Hash function has these main fundamental properties:

1. Collision Resistance
2. Preimage Resistance
3. Second Preimage Resistance

What is Collision of Resistance?

A collision occurs when two different inputs produce the same result. as We know that input here is always unlimited. Through the process, it produces an infinite amount of information output. But if two different inputs of infinite length have the same result as the length, then there is a collision. The hash function is widely used in the world of cryptography to validate transactions. This is an important feature of the hash function that gives the same result to two separate contents of the input data, and this process is known as collision.
It is like a collision resistance that does not allow the same output to be generated from two different inputs, it is almost impossible to prevent a collision while a collision can occur if the possibility arises.

What is Resistance to preimage?

This means that within the hash performance range, it is impossible to calculate the input of the element mapped to that element. Preimage is only way to straight path, for functions whose input and output are the same size, it is only one-way and unchanged. It is very difficult to find input from any output value. The preimage resistance has the property of a hash function, and accordingly, it is very difficult or impossible to generate input from a certain output if the user input is provided.
This feature is a hash function that makes the hash process more secure,The output length must be at least 80 bits. Preimage Resistance is the idea that the robust hash algorithm is the same, that is, before the image resistance. It is impossible to reverse this feature of hash performance. This is a way to save hash function. But if an unauthorized person reverses the output, he can attack.

Use tronscan and etherscan to verify the hash of the last block and the hash of that transaction. Screenshot is required for checking?

To view the last block hash and latest transaction hash, we will type on google chrome Tronscan at https://tronscan.org. When you will click on first link then it will open you will scroll down little and see latest block:

Click on the last block on the lists of blocks then detail will be open. Block number is 31807614

It will display the block details, the detail of block hash is:

The latest transaction hash

Using etherscan to verify the hash of the last block and the hash of that transaction?

To verify etherscan last block hash and latest transaction hash, you will type on google chrome https://etherscan.io and scroll down, to see the last block: The last block on etherscan is block number 12798002.

Now click on the block to display the block details:

Now the block detail will be displayed, the block hash is

detail is

Now click on see more:

Then click on transaction:

The transaction details have been displayed, with a transaction hash

Tranaction hash is :

these are screenshort which i take from my account with snipping tool.

Generate hash using SHA-256, with CryptoAcademy and cryptoacademy. Explain the difference?

Step 01:

Visit https://passwordsgenerator.net/sha256-hash-generator

You will see this window

Step 2:

Write "CryptoAcademy " there. You will get the hash of your word.

Step 3:

when i show you will you will type "cryptoacademy" then the hash of your word will be change.

In your own words explain the difference between hash and cryptography?

Although they are the same, they are not the same, and the hash function is designed in such a way that due to the resistance collision, no two inputs can produce the same hash output. Therefore, cryptographic academies and cryptographic academies cannot create the same hash function. Some special keys are used when encrypting data in a way that is not done in the hash function. The hash function does not use any keys. In encryption, these keys are used by authorized persons to retrieve data. Only the authorized person has the keys. Only this person can access the data using the keys.
In the event that this key is leaked to a third party, encrypted information or data can be decrypted, so it is recommended that the key be of length so that it is difficult to decide. In some cases, encryption uses a public and private key. Note that both private and public keys are separate, so by protecting the private key, encrypted data can not be compromised and can only be read by someone with a private key. This encryption is very secure and each key pair is very unique, encryption in this form can be called asymmetric encryption.
Encryption techniques and protocols to prevent third-party interference in a blockchain, to prevent access or retrieval of information from private messages during the communication process between the creator of the content and the end of the preparation process. On the other hand hash function is useful For security, confidentiality and anonymity, data is a cryptographic function used to encode data in a specific character string.

Hash Function:

1. Hash helps to identify data manipulation after signing as well as authentication.
2. The main purpose of hash function is to verify data.
3. The hash function is used to verify transactions.

Cryptography:

1. Cryptography is used to send secure messages.
2. Encryption encrypts all input data.
3. Length is not fixed here.

Conclusion:

A hash must be disputed because of the collision, this ensures that it is impossible to generate the same output hash for two different inputs. Pre-hedge resistance and impact are the three main features of hash. If it is a collision resistance hash, it is also a resistance to the second hypothesis. Encryption Protecting information and information encrypted by users who are not allowed to open the file, encryption using keys, keys to generate information in encryption and keeping the data or file secure. Used. Encryption requires keeping the keys secure because if disclosed, this key can be used to decrypt information. The hash and cryptography are method for securing your data from hackers i have learned a lot about this.
Thank you professor @pelon53 for this informative lecture.