Homework on Public and Private Keys - Questions

Blockchain and Bitcoin 101
#4888

  1. Public key is derived from private key. So it might be a hash function like f(private key) = public key. If you have the key pair, you can control the address.

a) as an address of a wallet
b) as a valid encrypted message

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#4889

  1. Describe the concept of public and private key with your own words.
    A cryptographic key-derivation algorithm takes an essentially random and unique input and generates a key pair (a pair of very, very big numbers) of a public and a private key, that are mathematically related in such a way that they can be used for encryption. The public key can be used to encrypt a message so that it can be decrypted only using the corresponding private key. The private key can also be used to sign a message so that the signature can be verified using the corresponding public key. Importantly, the private key cannot feasibly be derived from the public key.

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

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#4890

  1. Public key and private key are used in cryptography to encrypt and decrypt messages. Private key is a random number using which a public key is derived. If a person wants to send a message over unsecured network he can encrypt message using a public key published by recipient which is actually derived from the private key. The encrypted message can only be decrypted by the recipient who has the private key. Also it can be used to digitally sign a message.

  2. Encryption and Digital signature are two use cases used.

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#4891

  1. A private is your digital signature and with that a public key is generated to trade your coins

  2. Send encrypted messages and digital signatures

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#4892

  1. Private keys are used to generate public keys and you cannot find the private key from a public key. These keys allow for security.

  2. The two uses for these keys are encryption and digital signatures.

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#4893

  1. The public ket identifies who you are and is a destination. The private key verifies who is sending the message.

  2. It can verify who is sending the message, but it can also encrypt the message so nobody else can read it.

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#4894
  1. Describe the concept of public and private key with your own words.
    No private key = no crypto in the world of Bitcoin. Without the private key we are unable to get access to the coins and spend/send them. The private key generates the public key in one way and it is impossible to generate from the public key private key. The private key is used in the bitcoin world to sign the transaction (pin a digital signature).

The public key is also used in communication when we need to secure/encrypt a message that nobody else can see it except the receiver of the message (the receiver’s public key is used to encrypt the message). The receiver of the message can decrypt it using its own private key

  1. What 2 use-cases can public key cryptography be used for?
    Encryption and digital signature. The use case of digital signature has been used in bitcoin transactions
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#4895
  1. Public and private key cryptography is a verification and privacy protocol, in messaging application, my public key would act as an open locker than anyone can insert a message into, upon closing the locker (encrypting the message) no’one, not even the person who locked the message can unlock it except the person with the private key (owner of the key pair). Key pair’s are generated with a mathematical relationship that makes this possible.
  2. 2 use cases for public key cryptography are encryption and digital signatures, PGP uses public keys to encrypt data which can only be decrypted with the corresponding private key.In cryptocurrency/blockchain your public key generates wallet addresses to receive bitcoin to. When you send a transaction it is submitted to the network and signed by your private key.
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#4896

Private key is a large random number and a public key is a large unique number that is mathematically related to the private key.

“Each public key comes paired with a unique private key. Think of a private key as akin to the key to the front door of a business where only you have a copy. This defines one of the main differences between the two types of keys. The private key ensures only you can get through the front door. In the case of encrypted messages, you use this private key to decrypt messages”

(https://www.preveil.com/blog/public-and-private-key/)

There are 2 main use cases for public key cryptography or asymmetric cryptography

1. Encryption

"Public and private keys form the basis for public key cryptography , also known as asymmetric cryptography. In public key cryptography, every public key matches to only one private key. Together, they are used to encrypt and decrypt messages. If you encode a message using a person’s public key, they can only decode it using their matching private key.

Public and private keys: an example

Bob wants to send Alice an encrypted email. To do this, Bob takes Alice’s public key and encrypts his message to her. Then, when Alice receives the message, she takes the private key that is known only to her in order to decrypt the message from Bob.

Although attackers might try to compromise the server and read the message, they will be unable to because they lack the private key to decrypt the message. Only Alice will be able to decrypt the message as she is the only one with the private key. And, when Alice wants to reply, she simply repeats the process, encrypting her message to Bob using Bob’s public key."

(https://www.preveil.com/blog/public-and-private-key/)

2. Digital signatures

“Digital signatures employ asymmetric cryptography. In many instances, they provide a layer of validation and security to messages sent through a non-secure channel: Properly implemented, a digital signature gives the receiver reason to believe the message was sent by the claimed sender. Digital signatures are equivalent to traditional handwritten signatures in many respects, but properly implemented digital signatures are more difficult to forge than the handwritten type. Digital signature schemes, in the sense used here, are cryptographically based, and must be implemented properly to be effective. They can also provide non-repudiation, meaning that the signer cannot successfully claim they did not sign a message, while also claiming their private key remains secret. Further, some non-repudiation schemes offer a timestamp for the digital signature, so that even if the private key is exposed, the signature is valid.[14][15] Digitally signed messages may be anything representable as a bitstring: examples include electronic mail, contracts, or a message sent via some other cryptographic protocol.”

(https://en.wikipedia.org/wiki/Digital_signature)

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#4897

First answer will explain the use of the public and private keys pertaining to digital signature use.

  1. A private key is generated… and a public key, which is visible to the public, is spawned from that private key. The private key is used to send a message. When a private key is used to send a message that message is now signed. When the receiving party receive the message they can match that signed message ( private key ) with the public key that was generated from the private key. If the private and public keys correlate then the receiving party knows that the message is authentic.
    In summary, a paired private and public key validates the legitimacy of a particular message.
  1. Two uses for a public key.
    a. Encryption: used to send an encrypted message.
    b. Digital signature: used to verify a private key authenticity.
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#4898

  1. Public key is information that the public is able to see securely because it is encrypted by a private key that only the originator has.

  2. Encrypted messages and Digital signatures

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#4899

1- Public key is derived from the private key & can be shared with the public. Private key is used to decrypt messages & thus should be saved with owner only.
2- Sending & receiving messages $ funds, claiming rewards, staking & unstaking tokens.

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#4900
  1. Describe the concept of public and private key with your own words.

Public and private keys are how your wallet is secure and how you can send / access money in it. The private key is a generated for an enitty (user wallet) and it used to then generate your public key. This public key is the address you will use to recieve money from other sources / wallets and cannot be used to determine a user’s pviate key.

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

First : as a designation for a cyptocurrency wallet for were the funds should be routed to
2nd : as an encryption mechanism that can provide security to unautherizd access while sll allowing the details for sending information to be shared / found

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#4901

  1. A private key is a sequence of randomly generated numbers and a public key is derived from a private key.

  2. In cryptography , a public key can be used to encryption and digital signatures.

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#4902

  1. Your private key is a large random number that can be used to identify you. Your public key is derived from you private key and is also a large number but it cannot be used to identify what your private key is. However it can be used together with your digital signature to verify that something is signed by you.

  2. Encryption and digital signatures. Digital signatures is very much used in for bitcoin transactions.

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#4903

1 public key is a string of numbers that can be known to the public and be used to send things to that person via the public key and the private key is something you should keep private because this gives you acces to your funds.

  1. digital signatures and encryption
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#4904

1- A Private key is used for decryption of data while public key is used to encypt data such as messages, files, transactions etc.

2- Encypted private messaging & indentity confirmation

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#4905

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

Your computer can generate a private key and from the private key, you can generate the public key.

The public key can encrypt a message and the private key can decrypt the message.

The private key is the more important key, without it you cant decrypt a message sent with the public key

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

Bitcoin wallet with a public key. Use case: your bitcoin wallet can generate a private key that gives you access to the wallet and from that private key generate a public key that displays your Bitcoin address that can be shared with people that want to send you crypto

Signing with your private key. Use case: verifying that you’re the one who sent a message.

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#4906

  1. The concept of public and private key allows more security, privacy and integrity in transactions of all kind (message, financial transactions. One owns a private key. The private key is a random number that is generated by the computer. Based on that, a public key is derived. Everybody can see the public key. The private has to be kept private and secret. It is not posible derive the private key from the public key. It is a one-way-function.

  2. The concept is used for encryption and for digital signatures.

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#4907

1- The private key is used to generate your public key. The private key in turn allows you access to that public key (ie your btc wallet).
2- Two use cases for public key cryptography are digital signatures (proof of identity), and encryption.

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