Crypto Academy/Season 3/Week 2- Homework post for by @pelon53 by @kelechisamuel

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

The lesson gives understanding of Hash and Cryptography and their explanations , uses and nature .

• Resistance to Collision could be seen as a feature of a hash function that it can be calculated to find two connecting /colliding inputs . In other words we could say that a Hash function M ,is collision resistant ,if it's almost impossible to find two inputs that could hash to a particular output where the outputs B and C are not equal to each other but the product of M and B would be same as the product of M and C . Mathematically M(B) =M(C)
  M Also , we understand that , the condition of a hash function to be resistant to collision is that the length of it's results would be should be 160 bits (this information is as of 2004)
  Collisions could be also weak or strong in an input ; We could say that collison is strong when it could apply to any two arbitrary outputs and said to be weak when it could apply to just one output

• On the other hand , Resistance to pre image could be seen as a hash function feature too that is difficult to invert , given a part in the range of the hash function should be impossible to calculate an input that leads/gives details about the event .
  This pre image resistance corresponds to a one way pattern using functions with same sized input and output domain
  Like the resistance to collision ,the second stage of resistance to pre image does a similar work but in the resistance to collision ,no message is given to the attcker to start with , instead ,he searches for any two messages ,but in the resistance to pre image ,the attacker has a message given to start with.

USE TRONSCAN AND ETHERSCAN TO VERIFY THE HASH OF THE LAST BLOCK AND THE HASH OF THAT TRANSACTION.

TRONSCAN

• I will be starting with the tronscan verification, first of all log into www.tronscan.org as you can see below

• Scroll down and search for the latest block and transaction like we can see below. Click on it to get more details

• Below are the hash of the block as required

• When you scroll down, you can find details of the transaction of the same block, and also see the hash of the transaction as required

ETHERSCAN

• First log into the etherscan.io

• Scroll down and search for the latest block and transactions, then click on it for more informations

• below are the hash of the block as required

• Below are the hash of the transaction, you can also see that the block number is the same

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.

• The hash generation for CryptoAcademy can be seen below

• The hash generation for cryptoacademy can be seen below

The difference can be seen in the initial capitalization of the first letters of crypto academy in the first one and it is evident that the hash is case sensitive and a change in case can change the hash

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

• The concept of Hash and Cryptography are considered almost same , but basically I consider them not same . Firstly we see a hash to be a function used to locate and direct data of different sizes to a same size and Cryptography to be use of strong patterns to secure communication against invading of third parties into privacy .

• In my opinion ,Hash and Cryptography are different in the sense that ,the Hash processes information and data into a particular structure making it impossible to reverse the process without opening the initial password whereas the Cryptography that uses a decryption and encryption process would always have a key that could be manipulated .

• Finally we could also deduce that where the main focus of the Cryptography is to make sure that information in a process is protected ,the Hash functions make sure that it hasn't been altered or meddled with it (it is still in integrity)

Thanks for going through my post

Cc
@pelon53