Homework on Public and Private Keys - Questions

Blockchain and Bitcoin 101
#4447

1 - Private key is a random computer generated number, that must be kept secure and secret. A public key can be generated from the private key and is available for everyone to see.

A message can be encrypted using someone’s public key and that message can only be decrypted using that person’s private key.

A Bitcoin address can be generated from the public key and be used to send or receive coins. Only the person who has the private key for that address can send or receive the coins.

2 – Encryption and digital signature.

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#4448

  1. Describe the concept of public and private key with your own words.
    Private key is a randomly generated number that is used to sign your transactions. Only person who generated the private key should know what number it is.
    Public key is a number derived from private key, public key can be seen by anyone and it is created so that it is possible to verify the transaction.

  2. What 2 use-cases can public key cryptography be used for?
    a) Verification of transactions - digital signature.
    b) Making some information a secret - encryption.

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#4449
  1. A public key is derived from the private key and is visible to everyone, while the private key is specific to the individual using it (unavailable to the public) and should be kept secret.
  2. The 2 use-cases are encryptions and digital signatures.
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#4450

Homework on Public and Private Keys - Questions

The public key is somewhat a mask, the public key cloaks and jumbles up a secret message for no one to read. While the private key is used to un-jumble the secret message and then be read by the private key holder.

  1. (Encryption): A private and public key pair, can receive encrypted messages with the public key and then decrypt the secret message with the private key.

  2. (Digital Signatures): Example; Alice’s digital signature - which is generated by Alice’s private key - and Alice’s public key work together in order to verify that that Alice sent the message and not someone else.

17/05/2021 - Truls-Magnus

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#4451
  1. The private key is the key you use to decrypt encrypted files, it is yours only and should not be shared with anyone, if someone gets their hands on the private key they can unlock encrypted files . It takes form as the seed phrase you’re given when getting a wallet. It’s used to sign transactions as your digital fingerprint

Public key is the transparent version of your private key, it has a completely different hash but is connected with your private key. It is used to encrypt files, it is what you use to receive transactions when asking someone to send you bitcoin for example.

  1. A) The asymmetrical key pair are used to verify transactions (digital signature)
    B) To encrypt information
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#4452
  1. A private key is your ID - digital signature. It is improbable to be matched or repeated . Your private key is used to create a public key to transact with but your private key can not be decrypted from the public key
  2. Sending bitcoin . Sending messages
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#4453

Homework on Public and Private Keys - Questions

  1. Describe the concept of public and private key with your own words.
    Diffie-Hellman got the Nobel price for that and without them there is no secure connection via unsecured internet or SSL certs for secure browsing or any kind of digital signature.
    Based on Prime Numbers private key is generated and from that via mathematical formula public key is created. Public key could be shared with anybody on unsecured internet but messages encrypted by public key could only be decrypted by private key. Diffie-Hellman you have my gratitude for this.

  2. What 2 use-cases can public key cryptography be used for?
    Encryption and Digital signature (mostly used for blockchain)

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#4454

Public key can be used to encrypt data by anyone, but only a person with the relevant private key can decrypt it

  • Encrypting data: hiding what the data is from the world
  • Digital signatures: verifying who has created/sent the data
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#4455
  1. Private keys are huge random numbers used to generate public keys, which cannot in turn be used to reverse-engineer the private key.
  2. You can sign a message/transaction with your private key and the recipient can check it against your public key to verify your identity. You can also use the recipient’s public key to encrypt a message that only they can decipher using their private key.
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#4456
  1. Public and private key are encrypted codes randomly generated to transfer, decrypt or verify users. Private keys are an individuals secret key that is needed to send currency, messages and data, while public keys are used to accept messages, currency and data.
  2. To encrypt data and verify digital signature.
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#4457

Public key means just that. the public can read it or use it to send
.private is for your use to keep things safe and decrypt encrypted messages sent

Encryption and signature are two uses

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#4458

  1. Private key is large random generated number and it needs to be kept safe, it is used to decrypt messages, but it can be also used to encrypt messages.
    Public key is generated from private key, it is shareable and it is used to encrypt messages. Public key can only be decrypted by the private key.

  2. Public key cryptography can be used to encrypting messages and for digital signatures.

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#4459
  1. Public and private keys are cryptographic tools that can be used to for security and identification purposes.
  2. Public key cryptography is used in blockchain transactions. The public key is the address you share so other people can send you Bitcoin to that address. The private key is what grants you access to the funds sent to the public key, which was derived from the private key.
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#4460
  1. Describe the concept of public and private key with your own words.

Public key is visible to all and use to encrypt. Private key is visible to owner only and used to decrypt and sign.

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

When creating a transaction the public key is used keep it away from unintended purposes . When receiving the asset the private key is then used to verify ownership.

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#4461

  1. Describe the concept of public and private key with your own words.
    -A Private Key is a randomly generated, alphanumeric combination, unique to it’s user - used for decryption. A Public Key is a randomly generated, alphanumeric combination, derived from the user’s Private Key - used for encryption.

  2. What 2 use-cases can public key cryptography be used for?
    Public Key cryptography can be used in the cases of encryption/decryption and verifiable digital signatures.

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#4462

  1. Describe the concept of public and private key with your own words.
    A public key is open two view for everybody and is derived from a private key that identifys an according counterpart. To verify a transaction, a recipient gets a public key thats derived from a private key and can thereby be assured, a certain transaction was initiated by the correct counterpart.

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

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#4463
  1. These are phrases or codes that are encrypted in order to check and verify the sender and receiver. But these are also only one way direction in such the private key is the only key that can make a public key, and not visa versa.
  2. Digital signatures, and encryption of keys or messages.
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#4464

The Private key is encrypted and used as a signature to prove it comes from the owner, it is secret and randomly generated by a computer. The public key is seen by everyone but required.

Two use cases for public-key cryptography are digital signature messages and cryptocurrencies.

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#4465

Homework on Public and Private Keys - Answers

Notes:

  • Use cases of public key crytography
    • Encryption (i.e. send someone a secret message in a public forum with a lot of spectators around)
    • Digital signatures: how we can identify yourself and ensure integrity of a particular message
  • Decentralized wallets rely on public and private keys
  • Encryption expanded
    Process of generating private/public keys and how they encode/decode messages
    • Computer generates random number which becomes the PRIVATE KEY
    • Using a hash function the PUBLIC KEY is derived (output) from the private key (input)
    • Everyone has access to the public key but only one person (the owner) has access to the private key
    • Anyone can write a message and use someone else’s PUBLIC key to encode the message. Only the owner of the private keys can use the private keys to decode the message
  • Digital signatures expanded
    Example Alice sends message --> Bob
    • Both Alice and Bob have private keys which also generated public keys
    • Alice generates a message --> uses her PRIVATE key to generate her unique digital signature to “sign” message --> and then uses Bob’s PUBLIC key to encode the message
    • Bob can then use his private key to decode Alice’s message and read it
    • Bob can validate that the message was sent by Alice by validating that the digital signature and the sender’s public key were generated from the same private key (which in this case belongs to Alice). Another way to word this is that Bob checks to see if the digital signature is from the same private key that generated the public key (in this case Alice’s public key)
  • You create a wallet (i.e. MetaMask) --> they generate a private key for you (random number) --> private key generates public key --> public key generates Bitcoin address (or other blockchain address)
    private key --> public key --> Bitcoin address (can’t go in reverse direction)

1) Q: Describe the concept of public and private key with your own words.
A) Private keys are a random number/code generated by your computer. The public key is derived from the private key (private key --(hash function)–> public key)

2) What 2 use-cases can public key cryptography be used for?
A) Encryption & digital signatures

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#4466

1.Private is a randomly chosen number that is used to generate a public key using a hash function.
2.Public and private keys are used to encrypt messages or to provide a digital signature

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