Homework on Public and Private Keys - Questions

Blockchain and Bitcoin 101
#263

  1. Public key is generated from private key and is unique. We can share the public key but private key must stay hidden and only we can know it.

  2. In case that we want to send encrypted message that only one person is able to decrypt and read we take that person public key, encrypt message with that key and the message can be decrypted only with that person’s private key. No one else have that private key.
    In case of bitcoin we need public key to receive the BTC and private key to send BTC. That means that everyone is able to send BTC to my wallet but I’am the only one that is able to spend it because only I know my private key.

#264

  1. The concept of public and private keys are to enable the ability for an individual to send or receive encrypted messages over a network. The public key allows for the message to be received and the private key enables the unlocking of this.

  2. Encryption to help secure communication / transactions. Digital Signatures allowing to confirm that the transaction is good.

#265

  1. Being able to get onto the network and interact with crypto because the private keys allows you to sign for your transactions to prove that it is your funds you are sending. And the public key is derived from the private key and important to allow you to get an address as the identification of the account for people sending crypto to you.

  2. Encryption and digital signature

#266

  1. A public key is a number that is derived from a private key that can be safely shown in public because it is impossible to derive the private key from the public key.
    A private key is a random number that is used to sign transactions or messages to ensure only the owner of the private key could have authorized the message or transaction.
    Another way of putting it would be that a public key is something that can be interacted with from outside entities, and the private key is needed to access the results of these interactions.

  2. Encryption and signatures.

#267
  1. A private key is a randomly generated set of numbers which in turn can generate a public key. The private key is used to sign a transaction to validate the true origin of such transaction. Therefore anything encrypted by a public key can only be decrypted by the private key, one way function.
  2. For encrypting messages and digital signatures.
#268
  1. SHA 256 encryption is a unidirectional computational process. The alphanumeric string output is ‘strictly’ unique to the digital information it is derived from so the only way to ‘crack’ it is by randomly generating possible combinations of data until the correct private key sequence is discovered. This mathematical number is ‘close’ to infinite so the chances of solving it this way are ‘highly’ improbable but still theoretically ‘possible’. The private key is a randomly generated ‘large’ number and this forms the input of the public key. So the public key ‘is’ the output of the SHA 256 algorithm of that randomly generated large number.
    Hope this helps.

:blush:

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#269

  1. A) The private key is randomly generated and unique, as the chances of the same number being generated more than once are ridiculously large. Can also make the signiture that attaches to cryptocurrency transactions. It must be kept secret and safe.
    B) The public key is generated from the private key, can be shared publicly, and cannot be reverse engineered to find the private key. It can be used to make your bitcoin/cryptocurrency address, which again is publicly safe.

  2. Public key uses:
    A) A public key can be used to send encrypted data across a public platform, to be decrypted by the public key issuer.
    B) It can also be used within cryptocurrency transactions to securely generate a wallet address.

#270
  1. A private key is your private signature. A public key is how you can control bitcoin that comes into your public address.Your computer can create a private key. Your private key can then create a bitcoin address and then a public address.
  2. sending messages. sending BTC.
#271
  1. A private key is created from a random number, that number is then run through a formula and its result creates a public key. A private key is never shared with anyone because its the key that controls the data. The public key is shared with the public and is used to receive data only.
  2. Public cryptography is used to encrypt data for privacy and for signing data to prove control of data.
#272
  1. A private key is a randomly generated number, generated by your computer (Question: how do you actually know your computer generates these randomly??). With a special formula, a one way function like a hash function, you generate the public key from the private key.

A) Encryption use case: sending private messages in a world where everyone would otherwise be able to read your message. The public key can be shared with the world for others to send you messages. The sender encrypts the message with your public key, so that you can decrypt it with your private key. After encryption, the receiver (holder of the private key) is the only one who can decrypt the message (not even the sender can).

B) Communication integrity use case: Digital signatures. In order to identify yourself as the sender of a message to the person receiving your message, you can sign your message with your private key (Question: but you shouldn’t share your private key with others, so what is actually “signing” a message with your private key?). The receiver can use the signature to create a public key that matches your public key, thereby verifying that you are indeed the sender of the message.

#273
  1. Private key is a random number generated and from that a public key is generated.
  2. It can be used to secure data at rest and in transmission and It can also be used to verify identity.
#274
  1. Describe the concept of public and private key with your own words.

A crypto wallet is basically a pair of public and private key on the blockchain. When someone needs to send a transaction, a random number (private key) will be generated and only he has it. Then a public key will be derived from the private key and everyone can see it. When a transaction happens, the user will broadcast a message signed by his private key to the public, and everyone can verify the transaction by comparing the message with the public key given to them.

  1. What 2 use-cases can public key cryptography be used for?

The 2 use-cased that public key cryptograph can be used for are encryption and digital signature.

#275

  • Describe the concept of public and private key with your own words.
    every computer can generate a private key :closed_lock_with_key: (is a random number, this is secret and unique for the computer that generated it).
    Applying a formula to the private key the computer can generate a public key🔑(this public key is open for everyone to be seen).
    the private key :closed_lock_with_key: can be used to sign a message. to verify the autenticity of the sender the recipient can match the public key of the sender with the signature on the message.
    the public key :key: of a recipient can be used to encrypt a message addressed to him to be sent on a open communication channel and ensure integrity. the recipient is gonna be able to decrypt the message using his private key.
    a public key can also be used to generate a bitcoin address for a wallet.

  • What 2 use-cases can public key cryptography be used for?
    Encryption and digital signatures .

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#276

a private key is a random secret number, from your private key you can derrive a public key and from this public key an address is generated.

#277

Homework on Public and Private Keys - Questions

  1. Describe the concept of public and private key with your own words.
  • a public key is visible by all on the network and is generated by a private key. Private keys cannot be identified by tracing back through the public key due to the encryption process
  1. What 2 use-cases can public key cryptography be used for?
    1. encrypting data being sent over the network for security
      -2) leaving an immutable digital signature on the blockchain
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#278

  1. a private key is a random string of 64 digits generated by your computer.
    a public key is generated out of your private key.

    1. sending encrypted messages so nobody can spectate the message (message to public key that can be decrypted by only private key that belongs to the public key)
    2. you can sign a transaction with your private key to make a signature so the ledger knows you are the true owner of those funds
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#279

  1. A public and private key is a pair of random numbers. The private key can be used to derive the public key but not vice versa.

  2. Message encryption and digital signatures.

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#280

  1. both keys are use for encryption message from peer to peer.

  2. to shareing with other on network

    in combination with sign can use to veryfing message .are they come from same person

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#281

1. Describe the concept of public and private key with your own words.

Public and private keys are a cryptographic system that helps to ensure the security of a transaction.
The public key is visible to all, while the private key needs to be kept secret, to maintain its value. The public key has a relation to the private key through the mathematic algorithm which created the pair of keys.

If person A wants to send person B data that only person B can read, then person A can encrypt the data with person B’s public key. Person B can then use their private key to decrypt the data in the transaction.

If person B divulges their private key to others, they will also have the ability to read the data.

2. What 2 use-cases can public key cryptography be used for?

  1. Confidentiality - encrypting data
  2. Digital signature authentication - validating an event is verified by the correct validators
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#282
  1. Public and private keys are components of a cryptographic pair of keys: a public key that can be known by everyone, and a private key that should be known only by the owner. This system allows a sender to encrypt a message using the recipient’s public key, and that message can only be decrypted through the recipient’s private key.
  2. Use-case 1 is encryption and use-case 2 is digital signatures.
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