Hello Everyone,

I am much grateful participating inthis week homework post by prof @pelon53. The detailed lesson on Hash & Cryptography was very comprehensive.

HASH

source

---

Hash is a function that numerically change over a smaller or bigger sum of information which is summarized in a single hash. Hashes are simple cryptography functions that helps users to create codes which are alphanumeric in nature in a given information, i.e. any given information will get converted into a 64 character alphanumeric code, in doing so, the data becomes secured and safe as well as unique for the user since the 64 characters codes are also case sensitive.

Characteristics of Hashes

---

• Hash codes are irreversible and unrepeatable and of settled length, thus, information they carry are exceedingly secure.

• Hashes have 64 alphanumeric characters which are unique and case sensitive making it secure and safe.

• Hashes have existed very long time ago since 1961

• Hashes consume much time to develop from the MD2 to SHA-256.

Cryptography

---

Cryptography is the method of securing a given information by ensuring and securing the information from the world with the use of codes. It helps clients by securing their transactions performed inside the platform. Cryptography are in three forms which are; Secret key, Public key and Hash function.

Question 1:-
Explain what does the resistance to Collision mean and what does the resistance to Preimage mean?

Resistance to Collision

---

This technology was discovered in the year 1978 by Sir Rabin. This term Resistance to Collision comprised of two different words, Resistance which is the ability to denied something from happening and Collision is when two different object or events bump into each other. Bringing these two words together we have ** Resistance to Collision** which is the ability to prevent two inputs to produce the same output.

For instance, considering two inputs i.e. A and B, the hash function would be H(A) and H(B) respectively. The two hash functions would exhibit a hash collision property when the two hashes are not equal to any value of the inputs A, and B.

This senario explains Resistance to collision in its simpler unit. A hash function will have a collision property if the difficulty in finding two inputs for that same output exists.

Resistance to Preimage

---

Preimage resistance is a component of a hash function that's difficult to alter, preimage resistance causes the output value to rehash itself and this can be conceivable but exceptionally difficult to discover since hashes are designed to secure it. To form a preimage resistance hash, the hash must be able to create a least 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 lethally harmed so that it is possible to determine the input of a certain output. This is very necessary as it provides security to users of the blockchain as it secures the hash code, hence no Preimage attacks. Resistance to Preimage are of two types which are; preimage resistance and second preimage resistance.

Second preimage makes it difficult for hackers to find two inputs which results to the same output using any means. An example is taking A as input and B as output and taking both the hash and input as the same. This property would imply that H(A) and B are the same but it is very difficult to attack and decode them. H(A)=B.

Question 2:-
Use tronscan and etherscan to verify the hash of the last block and the hash of that transaction. Screenshots are required for checking.

I will first start with Etherscan

• Visit the official website of Etherscan

• It portrays two options that are Latest blocks and Latest transactions.

• I clicked on the primary block within the latest blocks column. This shows key data of the block such as the block height, hash code, number of transactions and the block reward.

Block hash: 0xb7f6236f4416c9cb727fe924e415faf2a4f56834e434cc9e0c3b94adae196428
Block height: 12801901
Block Reward: 2.299735386121030189 Ether (2 + 0.299735386121030189)

• When you press on the number of transactions you'll see a lot number of transactions. Tap on any transaction of your choice to get its details like its hash, transaction value, block number and many others. I chose the second transaction.

Transaction hash: 0xbe50fa2f7ae8f2a9ee4894a399e127fcebc7e6515006c6b42772560afcc53bda
Status: success
Block: 12801901

• To confirm the transaction, I copied the transaction hash and searched in the Etherscan address bar. If both addresses are the same ypu will see the same transaction.

TronScan

• Visit the official website of tronScan

• On the homepage there are two groupings; Blocks and Transactions.

• I clicked on the second block, it provided me with details of the block hash, block height and block reward.

Block Hash: 0000000001e5a01bf5968117d6c7ae0cc9c9e3b9d8d3042f612f79c1df58ee04
Block Height: 31825947
Block Reward: 16 TRX

• Click on any transaction (I clicked the second one) you will get the transaction details like transaction hash, block height, status and rank.

Transaction hash: 999c30fbe3d70fd03925188734f9f4bfa7cdf59cfde9adfdcaaf4829dd501be1
Status: CONFIRMED
Block: 31825947

• To confirm the transaction, I copied the transaction hash and searched in the TronScan address bar. If both addresses are the same ypu will see the same transaction.

Question 3 :
Generate a HASH using SHA-256, From the word CryptoAcademy and from cryptoacademy. Screenshot required. Do you see any difference between the two words? Explain ?

• Search SHA-256 in the google search box and click on the hyper link SHA-256 Online to see the homepage of SHA-256.

• Our first input will be cyptoacademy which can be seen on the screensht below, and its corresponding hash.

output hash: 0592f5dd27dc72e675b2ab9c77487a69faaf84196597fa052ec099c18ee7c4c5

The next input is CryptoAcademy which is seen in the screenshot below, its corresponding hash code is:d03ca34b258e6e0fd06b2070dde61b50bd4eef6161a8edaa4a420c9ae1beb7f9

Comparing the two hashes, we realised that the two hash codes are different for the two given inputs. This shows that similar input do not generate same output. The above is a clear expression of the collision property of hashes.

Question 4:-
Explain in your own words the difference between Hash and cryptography.

HASH

• The hash is a function that plays a vital part in cryptography, with it, it is possible to confirm the astuteness of the messages.

• Hashes make a very important part of in the blockchain technology.

• Each hash is made up of 64 characters that involve numbers and letters.

• In hashing, the data has a fixed length value

• Hashes aim at verifying the input data and secure this data with the alphanumeric codes.

CRYPTOGRAPHY

---

• Cryptography is a science whose objective is to protect the data of a third party.

• The length of data in Cryptography is not fixed

• In Cryptography, the input can be generated back from its output through the use of private keys.

• It is possible to obtain the original input of a data after it has been decrypted.

CONCLUSION

---

In conclusion, both hashing and cryptography are exceptionally significant ways of securing and exchanging data. Hashes have gotten to be the pivot of the blockchain because it has special and irepeatable codes which are profoundly secured and are generally utilized to name transactions on the blockchain platform.

Thanks For Your Attention