Homework on Public and Private Keys - Questions

Blockchain and Bitcoin 101
#1892

  1. Describe the concept of public and private key with your own words.
    - Public/ private key pairs are used to exchange encrypted information. Anyone wanting to send Bob a secret message can use Bob's public key to encrypt that message. That message can only be decrypted by Bob's private key. The message will remain secret as long as Bob's private key is not known by anyone else.
    - Public/ private key pairs can also be used to sign information. If Bob wants to guaranty someone that he wrote a message, he can use his private key to sign it. the receiver with use Bob's public key to validate Bob's signature.

  2. What 2 use-cases can public key cryptography be used for?
    1. Encrypted emails
    2. Sign Crypto transactions.

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#1893

  1. Describe the concept of public and private key with your own words.
    Encryption in which a private key is generated and a public key is generated from the private key. Hence the names, the private key isnā€™t meant for sharing for it controls what itā€™s meant to be a key for, while the public key is meant to be shared and acts as a layer between the public and the userā€™s private key.

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

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#1894

Homework on Public and Private Keys - Answers

  1. A public key is used to encrypt information and the private key is used to decrypt that same information. If I want to send a private message to my best friend I would use her public key to encrypt the message and send it to her and then she would use her private key to decrypt the message and read it.

  2. The 2 use-cases that public key cryptography can be used for are encryption and digital signatures.

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#1895

1.public key is shared with others so they can securely message you . your private key decrypts the messages you recieve.

  1. private keys are used to digitally sign and verify the sender of messages specific to a unique public
    key. used for both digital docs and crypto transactions.
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#1896

  1. A private key is a random generated number,
    the public key is derived from this number and can be used on open networks.

  2. Digital signatures and encryption.

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#1897
  1. & 2. In general when you have to encrypt a message or verify that a message was sent by a specific user and that itā€™s not been manipulated, thatā€™s where public and private key come into play. Basically the private key is simply a huge random number generated by your computer and itā€™s called private because itā€™s supposed to be kept so and not shared with anybody outside the user. The public key is mathematically derived from the private key and is open for anyone to see.

The first use case is encryption. E.g. Mike sends a message to Luke through an open network and doesnā€™t anybody to see the message. He encrypts the message using Lukeā€™s public key. That way only Luke can read the message by decrypting using his own private key (which acts in fact as a key to unlock the message).
The second use case is digital signature. Mike wants to make sure that the message sent to him by Luke was indeed sent by him. So basically when Luke sent the message he signed it using his own private key. Now the message has a signature ā€œappendedā€ on it. When Mike receives the message he can verify that the message was Lukeā€™s by taking both the messageā€™s signature and Lukeā€™s public and mathematically comparing both to verify that it was indeed a message generated by Lukeā€™s private key. If the operation of comparison is successful that means that truly the message was Lukeā€™s

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#1898

You can also encrypt data with it :slight_smile:

#1899

1)Private key is random alphanumerical number generated by the wallet/computer/yourself. It is secret and used to sign transaction and the only way to authenticate the transaction. Public key is generated from that Private key by some function/formula and it is shared with the public on internet. With the public key anybody can verify that the messages has been sent by the owner of the corresponding private key. Also, with the public key anybody can encrypt their messages to be only be decrypted by the holder of private key.

  1. 2 use cases
    a). Digital signatures
    b) encrypting messages over the internet
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#1900

Private key is a randomly generated key using mathematics. Public key is derived from the private key and public key can be shared across the internet to receive messages. Private key is not to be shared with anyone.

Public and Private key are used for encryption and digital signing in the blockchain.

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#1901
  1. Describe the concept of public and private key with your own words.

Private keys is a random generated number. Public keys are generated from private keys and public key will create a bitcoin address for an extra layer of protection. Public key is shared on the internet whereas private key is not shared and only you know. Private keys are needed to access the encrypted messages and used for digital signatures. There is no way to derive the private key from the public key. It is fundamentally impossible due to the numbers.

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

  2. It is used for encryption.

  3. It is used for digital signatures.

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#1902
  1. Describe the concept of public and private key with your own words.

Public and private keys are used for sending things over the blockchain. A private key is created and then the public key is derived from that private key. Other people, using the private key can send messages to the public key and it will turn the message into an encrypted message. That encrypted message can only be decrypted by the private key. Whoever is in control of the private key will be able to read the encrypted messages sent to the public key derived from that private key.

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

It can be used for sending private encrypted messages from one person to another, and it can also be used to make digital signatures. The digital signatures ensures mathematically who the sender is, or rather, where the transaction is coming from. It shows that it is coming from one specific private key.

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#1903
  1. Public and Private keys are a system whereby information can be encrypted using the public key yet can only be decrypted with the private key from which the public key was derived.
  2. Use case one: Sender A uses recipient Aā€™s public key to encrypt a file attached to an email prior to sending. Recipient A (or any holder of Recipient Aā€™s private key) can now decrypt the attached file for reading.
    Use case two: In use case one above Sender also digitally signs their email using their private key and includes their public key for Recipient A to verify that the message was signed by Sender A.
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#1904

1.) A private key generates a public key so that people can see when you send them a message or a transfer/transaction. Then the private key is just used as a means to confirm that it was actually you who sent the message or other stuff.

2.) Encryption and digital signatures.

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#1905

  1. Describe the concept of public and private key with your own words.
    A public and private key pair are necessary for cryptography. A private key is randomly generated while the public key is derived from the private key (impossible to derive private key from public key). Private key acts similar to a password in that it should be kept secret because it is used for decrypting messages and verify you as the sender of a message. The public key is like a username.

  2. What 2 use-cases can public key cryptography be used for?
    One of the use-cases is to encrypt and decrypt messages. Another is to digitally sign a message so that the recipient can identify the sender thereby verifying the integrity of the message.

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#1906

1.Describe the concept of public and private key with your own words.
Public key you can put it on your twitter or facebook and there no problem but
your private key is only for your us dont share it .

2.What 2 use-cases can public key cryptography be used for?
Signing digital documents or encrypted email and the only one who can encrypt the
message is the private where the message was send to

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#1907
  1. A private key is a randomly generated, astronomically large number from which you can generate a public key. Like the aforementioned hash function, the generation of a public key is a one way process from private to public but never from public to private.

2.Public key cryptography has two use cases - encrypted messaging for privacy and digital signature for sender verification.

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#1908

Q). Describe the concept of public and private key with your own words?
A).The keys are simply large numbers that have been paired together but are not identical (asymmetric). One key in the pair can be shared with everyone; it is called the public key. The other key in the pair is kept secret; it is called the private key. iN MYWALLET/BACKPOCKET.
Q). What 2 use-cases can public key cryptography be used for?

A). 1).Online payments: PCI-DSS standards mandate payment card data (stored as well as in-transit forms) to be encrypted using algorithms such as AES-256.
2).Emails AND Messages: Email encryption helps to protect sensitive information sent through email channels. Public key encryption methods along with digital certificates are usually the methods used for securing email communications.

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#1909
  1. With the private key I can sign my transactions and the public key verifies that I am the owner or sender.
  2. Send messages or funds.
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#1910

  1. A private key is a number, only the holder of the key should know and doesnā€™t tell anyone else. It should be a huge random number, which is statistically impossible to be randomly created two times. A public key is derived from the private key through a complex algorithm. It is impossible to derive the private key from the public key. The private key allows the holder to prove that he has the private key corresponding to a public key. The public key - as the term implies, is known to other people or even the whole network, but only the holder of the private key can show that the public key was generated with his priave key.

  2. encryption and digital signatures.

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#1911

The private/public key pair uses a public key to encrypt and a private key to decrypt. A private key is a large random number and a public key is mathematically calculated from the private key in such a way that a private key cant be derived from a public key. This allows the public key to be shared. Public key generated by Elliptic curve has a smaller key size but with the same security strength. Encryption is used in communication like SSL, SSH etc.

A digital signature is a way to verify the authenticity of a sender and that the content is intact without disclosing private key. We are using Elliptic curve to generate a digital signature(one-way function) by attaching a private key with content (hashed). With senderā€™s public key, a signature and the content hash thereā€™s enough information to prove that if the private key used to sign is associated with a public key. Digital signature is used widely in cryptocurrencies to verify transactions.

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