Crypto Academy Season 3 Week 8 - Homework Post for @stream4u CryptoGraphy

Blockchain technology brought about advanced changes in terms of security and privacy before its inception transactions done among users are solely under surveillance either from the centralized financial systems or government officials, these gave multiple users the notion of being monitor in every large transaction they are conducting with these big organization would prefer to conduct a basic transaction using checks or direct contact to counter direct or indirect monitoring.

Blockchain CryptoGraphy

With blockchain technology, digital encryption was achieved through cryptography making it possible for users to send transactions and massage in an encrypted format that can only be decrypted by the recipient.

Cryptography is coined from two words crypto which means secret while cryptograph which is using computer language to write secret words.

Blockchain cryptography integrate the use of blockchain technology to secure the network protocols making transactions, sending, and receiving of messages among users private against public access.

How it works

There are key important features that are needed for blockchain cryptography to be achievable the sender the receiver and finally encryption and decryption keys once both parties are connected to the right blockchain server and internet then transactions, sending and receiving messages can be communicated.
The encryption key and decryption key are unique features in blockchain cryptography as they made it possible for users transactions to be inaccessible to the public.

Therefore primary purpose of blockchain cryptography is to safeguard and ensure all transactions conducted among users are encrypted against public access only the recipient is eligible for decryption of such transactions.

Importance of blockchain cryptography

• With blockchain cryptography transactions in digital cryptocurrency are made anonymous through the use of cryptography.

• Blockchain cryptography guarantees the security of users' transactions.

• It prevents double-spending of cryptocurrency.

• Blockchain cryptography is also used for the verification of crypto transactions.

Mention a few names which are the Blockchain Platforms?

Examples of blockchain platforms that use blockchain cryptography include.

• Monera blockchain is one of the leading blockchain technology that ensures users privacy are of primary priority it's a top notch blockchain platform that has integrated the use of blockchain cryptography to keep users transactions anonymous.

• Zcash blockchain is another blockchain protocol that integrates the use of cryptography to secure it, users' transactions Zcash uses a cryptographic tool called Zero-Knowledge Proof and grants participants an option to shield transactions.

In the blockchain, cryptography public key is cryptographic code that can be accessible by the general public it can be used by users to receive cryptocurrency from other users just like a user wallet address which can be shared with the public for transaction purposes the public key plays the same role as well.

In essence, the public key in cryptography can be publicly distributed without any security compromise.

The public key is an alphanumeric key that is generated in a user's wallet used for facilitating users' transactions, it is also used to verify user digital signature and proof of users ownership.

In general, how the public key works is it helps initiate transactions in the blockchain through a user crypto wallet with the help of a private key these initiated transactions are completed.

The private key work simultaneously with the public key although the private key as the name suggests it should be made private and not accessible by the general public it with the private key one is eligible to control transaction processing in his wallet.

Private keys are only made available to the user which helps such user facilitates all chain transaction.

When two users decide to initiate a transaction their public key will be shared the public key is a hash version of the public address used for sending and receiving digital tokens. The private key helps in generating the public key while the public key helps in generating the public address for making transactions among the two users.

Just like in centralized finance systems where a check issuer needs to sign a written signature so to ensure proof of ownership of his account.

In cryptography digital signature works, in the same manner, the only difference here is that it's in a digital format/coding which makes it more authentic.

Digital signature in cryptography is used to increase/stimulate the security level of digital transactions among users it involves using two keys the private key which is used for signing all transactions and the public key which is used for verification of users transactions.

Therefore in general terms, the digital signature in cryptography is used for authenticating a user's ownership over his wallet It is used for identifying a user as the authentic owner of a wallet sending a message or transaction.

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The above image shows a typical example of how a cryptographic digital signature works.

For these processes to be completed there must be a sender who owns a private key and also a receiver who can receive public keys and decrypt such public key with is price key the private key serves as the secret channel between the two parties and with private key the receiver can easily decrypt and read the senders message.

Symmetric cryptography

Symmetric cryptography is known as symmetric encryption this process of encryption requires the use of one secret key also known as the private key these single keys can be used for encryption and decryption of messages

In general, the term symmetric cryptography uses one key for encryption and decryption of messages and transactions

Asymmetric cryptography

It is the opposite of symmetric cryptography or encryption in this type of encryption two keys are required public and private key which are used for encrypting and decrypting massage.

Here the sender uses the public key to initiate transactions or massage while the receiver uses the private key to decrypt what was sent by the sender

Difference between symmetric and asymmetric cryptography

Symmetric	Asymmetric
It requires the use of a single key for both encryption and decryption	it requires two keys public and private keys for encryption and decryption

Symmetric	Asymmetric
The sender needs only one key to perform both tasks of decoding a message	public and private keys will be needed to the task of decoding a message

Wallets in the crypto space are used for sending, receiving, storing cryptocurrencies like bitcoin, and other alternative altcoins.

How blockchain wallet works

Three important features are needed in any blockchain wallet these include an address, public, and private key all the three elements are required for any user to establish a complete transaction on the blockchain.

The address that is generated in each wallet is used by a user to receive payment the address can be shared with the public and anyone can access it and make payment with such an address the generation of an address in the blockchain wallet begins with the generation of a private key simultaneously the public key is also generated from the corresponding private key.
The private key grant the crypto user ownership over his crypto fund with the private key he can be able to sign any transaction.

In general, the blockchain wallet helps a user automatically store these private keys and helps in completing any transaction.

Here users are meant to understand that with the help of a blockchain wallet the **address, public and private keys are been generated automatically once a user creates his wallet account phrase keys or recovery keys are what gives a user complete control over his wallet with the phrase key a user can easily recover or reset his blockchain wallet.

A typical example of a blockchain wallet that uses cryptographic technology for sending and receiving purposes is the blockchain.com wallet.

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It can be accessed from a web browser and on mobile devices.

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Merkel trees are an important aspect of blockchain technology database storage is important in every technological innovation blockchain use up a very large number of data to store up transaction information on its blockchain with the implementation of Merkel trees structure it made it possible for block size to be reduced making it more accessible for users to verify and filter block transaction information.

Therefore a Merkel tree is a data structure that is used for securing blockchain transactions, verification of transactions, and also used to reduce blockchain data storage size.

It makes it possible for blockchain to share data in a transparent manner organize data for verification in an orderly manner.

How it operates

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The Merkel tress works in a way of getting all transactions details in a block and put them in a single tree structure this makes it possible for this system to summarize all block transactions and makes it easy for users to verify a transaction and easily filer which transaction is not part of a block.
Hashing in Merkel tree helps provide the block with hashing of pairs and nodes this help to make sure there is no duplicate or error in any transaction it is done repeatedly until one hash is left this process is known as the Merkel Root

Importance of Merkel tree in blockchain

• Merkle tree in the blockchain is used to verify the validity of a data, such as transaction verifications

• Merkle tree reduces the size of blockchain storage space

• It can be used to verify information quickly by separating large information into smaller sizes.

I will be accessing the blockchain demo website here blockchain demo

At the top right corner of the page, four basic elements which are very important in cryptography these include key, signature, transaction, and blockchain

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Public/private key on the blockchain demo

Before going further it should be noted that private keys are not to be shared with any external party it should only be used by the user also it should be noted as well private keys are used for generating the public keys which I will be exploring below.

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Private key
54193461273726024081681564020988056979819917391897592279873175462587231506004

Public key
04ee109de2effb0c265493fc1e56580495f3df035ce5d50500325dd662ca4711b1c4eca38ef343694fdb918fa73513f77314413d7507c6385dce3e3fce695d23a2

Above is typically an example of a public and private key in the blockchain it can be obtained from the screenshot the public and private keys are combinations of a string of alphanumeric long numbers and alphabet which are combined to randomly form the private and public key.

Next step I will be altering the private key this will help me understand how every private key I input will be creating a new public key.

This is why I stated earlier that the private key is used in generating a public key now from my screenshot I will input my private key as number 2

Below was my public key generated by inputting 2 as my private key.

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Private key
2

Public key
04c6047f9441ed7d6d3045406e95c07cd85c778e4b8cef3ca7abac09b95c709ee51ae168fea63dc339a3c58419466ceaeef7f632653266d0e1236431a950cfe52a

Again, I will change the number and add 3 to the private key to observe the new changes in the public key

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Private key
3

Public key
04f9308a019258c31049344f85f89d5229b531c845836f99b08601f113bce036f9388f7b0f632de8140fe337e62a37f3566500a99934c2231b6cb9fd7584b8e672

Above is the new public key generated this shows as the private key are been altered or changed the public keys are as well changing simultaneously.

In general, any number can be used as a private key which in turn can be used to generate a new public key used in blockchain transactions.
This is why the public key can be viewed by anyone while the private key is meant to be kept secret.

Functionality of keys

The private keys generated on the block are used for signing transactions and in turn, the private key is used for generating the public key the keys function to validate transactions on the block

Signing in blockchain demo

In other to sign a transaction on the demo blockchain I will need a private key and also a public key these will give me access to sign or verify a transaction.

Below I will be generating a random private key by clicking on random these will generate a valid private key and a valid public key which can be used for my transaction.

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Random private key
94641776275083168063738893493928376676644396449169095865222664406475533765374

Random public key
044fb4b32ddc72a47e7ce26d76ed3624b080820abd613346d9ea2644465510afdfca83c63680630d4e9b5b07ccad9d9b92dec512674938d414c24e6c16fc6fcf2c

By clicking on the random bottom I generated a valid private and public key these will help me generate or sign a transaction by clicking in signature I will verify a transaction.

Clicking on the signature I input the message Hello steemit

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Below is my generated private key which can only be used to sign or verify the above message.

private key
43244449736614749078403976974862973418556364798491979709689730207333397110550

When I clicked on the sign the below message was generated

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Message signature
3046022100ecf9e2e0a50491d777c7ed2d62c92721a91ebe6e5b4c5dca52089f0f10f2a7ce022100a40dfd861b6294f8de52253ff531ccd93a70f5f704bb263b82b3e73017759b11

When I clicked on the verify at the top left corner my public key was generated.

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public key
0415cb064efe827a6a66f54a2c0d1d3fb1ce71f8a14bc23ce76a6348211f9b225a0d6f4e2140c561b1ed4dd709908807b42f9c294eb4e8640d83bf5c35436da52c

With the public key which was generated from the above private key, I can now be able to broadcast or verify my signature by making my message go public or send to a different user.

By clicking on the verify it can be seen below how my dashboard turns green which means the transaction/message has been sent successfully

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Functionality of signing/signature

Signature works/function with a private and public key it is used to shows ownership over a signed transaction.

Transaction on demo blockchain

Clicking on the transaction I was redirected to the below page.

It is known for any block transaction to be completed there will be a private key

private key
56467712501216161576967848528090525587928621544025662780861658475352109842217

There must also be two addresses for the sender and the receiver.

From 047f684b1f0312261068be0ec413bc678cc982f6a7236ec2fdda5055143172495dcbbd210b010697559ec604237fefaf60d06b9c2373a868d06570669bcaba0be1

To
04cc955bf8e359cc7ebbb66f4c2dc616a93e8ba08e93d27996e20299ba92cba9cbd73c2ff46ed27a3727ba09486ba32b5ac35dd20c0adec020536996ca4d9f3d74

Above are the two addresses generated for the transaction.

There must also be an amount needed to complete the transaction above $20 was used.

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By clicking on the sign a massage signature was generated.

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message signature
3046022100c6e6d4d721bb39e3771435569282e99dd1484568037d528bb50cf0684ca2227e022100d38e5e07549128f677a4c056b79d75599051e6ce690aed1956c9434f541ed8cd

Then I will click on verify to generate my signature which can be used to broadcast the transaction.

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Signature
3046022100c6e6d4d721bb39e3771435569282e99dd1484568037d528bb50cf0684ca2227e022100d38e5e07549128f677a4c056b79d75599051e6ce690aed1956c9434f541ed8cd

By showing green it means my transaction has been completed and sent to the receiver.

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Functionality of transactions

Transactions function to complete a block transaction.

Conclusion

Blockchain cryptography is a very broad topic it plays a vital role in the development of blockchain technology as it is known security and privacy are what make blockchain technology very unique with cryptography this was achievable making block transactions be executed in a secure decentralized manner.

Private keys are important as they can not be disclosed for public use it's the secret key that makes all transactions to be processed on the other hand public keys can be made public for other people to access just like the blockchain address is used for receiving payment.

Blockchain wallet functions with private and public keys and stores all these keys in the blockchain wallet for users to perform transactions and signing.

With the help of a blockchain demo account users can practically see how private keys and public keys are generated which are used for signing and validation of all block transactions.

This is overall an important topic that can't be overlooked in blockchain technology.