Homework on Public and Private Keys - Questions

[tapptress]

1. Describe the concept of public and private key with your own words.
   A private key is kept secret and is used to generate a public key that can be shared.

2. What 2 use-cases can public key cryptography be used for?
   Public key cryptography is used in encryption and digital signature. A message can be encrypted using the public key of the person receiving the message and they will use their private key to decrypt. A private key can be used to digitally sign something and the public key can be used to verify the digital signature of the signer.

[stevenbowler]

1. Describe the concept of public and private key with your own words. Public key as named is shared publicly and can be used to address/locate a person/endpoint on the blockchain. The public key is derived from the private key. The private key is used to generate the public, and it is mathematically impossible to reverse-engineer/generate the private key, knowing just the public key. The private key is used to “unlock” any transaction on behalf of its owner. If an individual were to lose their private key, that could be catastrophic.
2. What 2 use-cases can public key cryptography be used for? 1. encryption and 2. digital signature which most relevant to the blockchain, where individual want to be able to uniquely identify their property/coins through the blockchain.

[Larsen]

1. Describe the concept of public and private key with your own words. A public key is for the world to see and is generated from the private key. A private key is for only the owner/holder of bitcoins.
2. What 2 use-cases can public key cryptography be used for? Public key cryptography is used as a digital signature to verify a private key. A public key is the only way to decrypt a message using a private key.

[magicnum3er1]

1. Describe the concept of public and private key with your own words.
   Public key is a huge numerical value used to encrypt data. Public key is derived from the private key.
   The messages or transactions can be sent out in the open for everyone to see using a public key because they are impossible to decrypt without the private key.

2. What 2 use-cases can public key cryptography be used for?
   Public key allows to send messages or transactions out in the open for everyone to see because it can not be decrypted without the private key.
   It can be used for digital signature

[Stephen_E]

@ivan

Homework on Public and Private Keys - Questions

1. Describe the concept of public and private key with your own words.
2. What 2 use-cases can public key cryptography be used for?

1. A digital address is secured by having the combination of a public key and private key. The private key is a random number. The public key is derived from the private key using a one-way function. Thus, during digital interactions, different users can interact using their public keys without fear that their private key will be discovered.

2. The two use cases are encryption and digital signatures. In encryption, a sender uses the receiver’s public key to encrypt a message. The receiver’s private key is the only number that can decrypt the public key infused message.
   In digital signatures, a sender can reveal their private key to the receiver. THe receiver uses the private key to derive the sender’s public key–this acts as verification that the sender is genuine.

[EndGame]

1. Public keys can be viewed by anyone while private keys should only be viewed by the owner. Encryption and decryption require both keys.
2. Encrypting transactions and signing them.

[Alko89]

@magicnum3er1

transactions out in the open for everyone to see because it can not be decrypted without the private key.

Transactions utilize digital signatures (you sign a tx with a private key)

[Alko89]

@EndGame

Encrypting transactions and signing them.

Transactions on Bitcoin are not encrypted.

[gcradduck]

1. A public key is a value publicly associated with a party. This public key, and its
   relation to the owning party can be safely broadcast to all the world, and any other
   party may use this key to encrypt data intended for the owner (of the public key).

The owner’s private key is a supreme secret, only to be known by the owner, never to be
shared with anyone.

If the owner receives data encrypted with the public key, he may decrypt the received message
by way of the secret/private key. Similarly, if the owner signs a message with their private key,
another party may verify the origin of this message, by applying the publicly known key to the
privately signed signature.

2. Within the blockchain, PK cryptography use cases include
   a) Encryption of data / messages
   b) Digital signatures, or the signing of transactions (by the initiating party who might be SENDING bitcoin, for example)

[T.O.B]

1. Describe the concept of public and private key with your own words.
   A private key is a uniquely generated code specific to a particular user.
   A public key is generated from the private key to allow encrypted transactions between the owner of the private key, and someone the owner of the private key wants to make an interaction with.
   The public key is generated from the private key and is used to confirm the private key in transactions.

2. What 2 use-cases can public key cryptography be used for?
   Encryption of messages to ensure identification of both parties.
   Encryption of transactions.

[Caraenache_Catalin]

1. The private key is a random set of numbers. This is used to create a public key, but the inverse process is not posible. Private keys are used to sign a string of information when we deal with a digital signiture, or is used to decrypt the information when this is encrypted using the public key.

2. They are used to encrypt data and identify the digital signature of its private key.

[vic21]

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

Public keys and private keys are used to encrypt and create digital signatures. In encryption, a certain party’s public key can be used to encrypt messages that are to be sent to that party. Once encrypted, the party can then use a private key to decrypt the message.

In digital signatures, private keys can be used to sign messages, which then can be encrypted using the public key of the party that is to receive the message. The receiver can then use a private key to decrypt the message and see who the sender was based on the digital signature.

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

Encryption and Digital Signatures

[Flippy]

1. private key is randomly generated key which decrypts a public key using that private key but it’s also a one way concept where you can’t do a vice versa thing.

2. Use cases of a public key is to encrypt a message and to digitally signing a documents.

[jahh]

1. whatever is encrypted by the public key can only be decrypted by the related private key
2. 1. a)encryption b) digital signatures

[Alko89]

@T.O.B

Encryption of messages to ensure identification of both parties.

Its called a digital signature where you can verify the private key of the message signer.

[ish]

1. Public and private key are used to encrypt and decrypt information. Public key encrypts information and private key decrypts information. Public key is generated from a private key and cannot be reversed.
2. Encryption, when sending information is encrypted and receiving information is decrypted.
   Digital signatures, verifying who sent or received a message or who sent or received Bitcoin.

[Acex13]

1. Describe the concept of public and private key with your own words.
   Private keys derive public keys and are randomly generated unique addresses - large numbers - that are paired or linked to create a locked relationship. Any message or transaction (in the case of bitcoin and other cryptocurrencies) sent to a person’s public key (public address) is encrypted with SHA-256 and can only be unencrypted (read or received) by the person holding the matching private key. If the receiver loses their private key, they cannot retrieve that data (message or transaction) and it is lost or unreadable forever.

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

[T.O.B]

You put it better than I.

[Alko89]

@Acex13

encrypted with SHA-256

SHA256 is not used in PK cryptography, for that the Elliptic curve function is used.

[TracyR]

1. A private key is a very large, unique randomly generated number. The private key is then used to create a public key used for transactions on the blockchain. The private key is also used to create a unique digital signature that verifies that you made those transactions. Neither the public key or the digital signature can be reversed to get the private key. Without the private key, access to money held on the blockchain is impossible.
2. Public keys can be used for encryption of information transmitted on any public forum or they are used in cryptocurrency as public addresses for transactions.