There are several assignments that must be prepared, the task I mean here is the homework given by professor @pelon53 in his crypto academy class. The discussion this time is about hashes and cryptography, I will immediately answer according to the question without any other description, there are 4 questions in his class by doing the following tasks:
1. Explain what does the resistance to collision mean? And what does resistance to preimage mean?
This is a unique function of hash, the so-called collision is the hash accepts different inputs but produces the same outputs. Although this is very rare, it doesn't mean it doesn't happen, it's just hard to find. resistance to collision is a cryptographic hash function that is designed in such a way that there is no collision with the resulting outputs.
As we mentioned earlier, it is not impossible for a collision to occur because the input input is unlimited while the output produced is limited. Before a hash function can be called a collision resistance, it must have a minimum length of 160 bits.
Preimage resistance is a component of a hash function that is difficult to change, preimage resistance causes the output value to repeat itself and this is possible but very difficult to find because hashes are designed to protect it. To make a preimage resistance hash, the hash must be able to generate a minimum of 80 bits before it can be said to be preimage resistance. The thing that can cause preimage resistance is when the hash algorithm is fatally damaged so that it is possible to determine the input of a certain output.
2. Use tronscan and etherscan to verify the hash of the last block and the hash of that transaction. Screenshot is required for checking.
How to see the last hash and block in transcan?
Open tronscan, then press the home button and the interface will appear as above.
Then click more, after that there will be an interface like the image below.
Click on the 31767251 block number so that we are directed to the block details.
Block details are displayed as shown below.
To check the hash of the last transaction we have to go back to the main menu, then click on transactions as shown above.
After clicking on Transactions we will be immediately taken to an overview of the last transaction hash, and the last transaction hash is:
To find out the last block and hash in Etherscan is also the same as Tronscan, the steps are as follows:
- Open ETHERSCAN, on the main menu directly click on the block code as shown below.
- After that we can see the details of the last block and also the hash of the block as shown below.
- Return to the main menu, scroll down then click on the last transaction hash to get the details, see the image below.
- After clicking, we can see the hash of the last transaction as shown below.
Note: this is the block and hash of the last transaction when I open Tronscan and Etherscan, for now the block and hash will change immediately due to the number of transactions that occur.
3. Generate the hash using SHA-256 , from the word CryptoAcademy and from cryptoacademy. Screenshot required. Do you see any difference between the two words? Explain.
Let's generate hashes for the keywords CryptoAcademy and cryptoacademy using SHA-256. Whether the hashes will be displayed the same or different, we will find out later after checking directly.
To do it is very simple, we only need to open passwordsgenerator then enter the word CryptoAcademy and the hash will be immediately displayed as shown below.
And the Hash shown for the CryptoAcademy keyword is:
D03CA34B258E6E0FD06B2070DDE61B50BD4EEF6161A8EDAA4A420C9AE1BEB7F9
As for cryptoacademy, the displayed hashes are:
0592F5DD27DC72E675B2AB9C77487A69FAAF84196597FA052EC099C18EE7C4C5
And it turns out that the hashes generated from cryptoacademy and CryptoAcademy are very different, what causes the difference between the two even though they both use the word #Cryptoacademy, the answer is a different input even though it has the same meaning or must be the same but the input is different, one use must be capital C and A while one more word using must be all small.
This shows that the hash has a non-repeatable characteristic, the resulting code is very different because we enter different inputs. In the first input, CryptoAcademy uses capital letters C and A, while the second input does not use capital letters.
4. In your own words explain the difference between hash and cryptography.
Following are some of the differences between hash and cryptography:
Cryptography provides security such as authentication and confidentiality, while hashing provides convenience in storing data. For example passwords are hashed and stored in a database.
Blockchain systems as well as indexing have wide uses for hashing and cryptography is fundamental to the operation of Blockchain.
Hash converts text or messages into random characters that have the same character, while cryptography maintains data and information based on security.
Hash provides security and privacy, while cryptography operates as an ecosystem.
CONCLUSION
I really appreciate the class given by professor @pelon53, thanks to the class he gave us to understand the importance of hashes and cryptography in Blockchain and cryptocurrencies. I personally didn't really understand this before, but now at least I have some new knowledge about hashes and cryptography.
I am happy to listen some feedback from the steemians if there are indeed many mistakes in my writing or the understanding I have given is wrong.
Regards.