Homework on Public and Private Keys - Questions

Blockchain and Bitcoin 101
#4227
  1. My wallet software in my computer generates a unique and long number. Impossible to have the same number anywhere. It is then transformed into another number using an algo. The first number is Private key, send number is the Public key. Private is secret and only know to me. The public can be known to anyone. To send me something secret, my public key can be used to encrypt the original information into gibberish, send across to me, and I can use my private key to decrypt and see the infomration.
  2. Two use cases are for Encryption/Decryption of secret information and Digital signatures
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#4228

Noted. Thank you so much

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#4229

  1. A private key for me, is like the key of my safety deposit box, it belongs to me only, and I can’t lose it. A private key is the safety deposit box, only my key can open it. These public and private keys can be used to verify actions as a digital signature or to encrypt and read encrypted messages.

  2. Signing important online documents to make sure that it really is you signing, and safe private two - way communication.

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#4230
  1. First you generate a extremely large random number of 2^256 through a computer program just to be secure. Witch is going to be your Privat Key. Then you take this number you pass it through SECP256k1 elliptic curve multiplication and we generate a Public Key (This formula has a special property called ‘‘trap door’’ you can only go one direction, you can only generate the public key from the private key and not other way around).
    And then we hash this public key twice through SHA256 then the result with RIPEMD160 and then the output is your hashed version of your public key.- then you take this hash it twice with SHA256 and the result you add it to the end of the previous function result. As this will be as a verification for the wallet software, to try to calculate the address out of the last few digits.
    This layer of security is in case someone gets a digit wrong, to not lose the bitcoin in the transaction.
    Then you have your User Friendly public key (Public Key + Check Sum)

2.Message encryption - transactions and Digital signature.

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#4231

Homework on Public and Private Keys - Questions

  1. Public key is the key you share with others to make a transaction and others use it to encrypt data only you can decrypt.
    The private key is unique, it’s the key you keep private and use unencrypted data so only I can read it.

2.Can be used to encrypt messages or sending funds.
Can be used for digital signature.

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#4232

  1. Describe the concept of public and private key with your own words.
    Public key is a random very long number which you computer generates and you have to kept is as a secret. From that private key you generate a public key which can be shared to everyone. Private key is the most important key since it is needed for accessing to your wallet and your coins. In case you have lost your private key you have also lost your coins. Meanwhile public key is used for interaction with other addresses in the network. You can also go from private key to public key but it is impossible to go in the other direction which means it is impossible that someone would guess the private key using a public key.

  2. What 2 use-cases can public key cryptography be used for?
    They are used for encryption and digital signatures. Encryption is used if you want to send a secret message to someone using a public network where there is a lot of other people involved and digital signature is used to verify is the message was really sent from that particular address or person.

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#4233

1. Describe the concept of public and private key with your own words.
A private key is a randomly generated large number. The public key is computed from the private key.
The public key can be shared wit everyone while the private key should be kept secret.
This is a one way function (like hashing), meaning one can never determine the private key from a public key.
Now, we can encrypt data (i.e. messages) using the receivers public key. This encrypted data can only be decrypted by the receiver using his private key.

2. What 2 use-cases can public key cryptography be used for?
Encryption and digital signatures.
Encryption can be used to encrypt a message going through an unsecure channel.
Digital signatures do not encrypt data but on can verify that the data has been sent from a specific sender.

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#4234

1: A private key is a computer generated number that is able to decrypt data that is sent through the related public key. A public key is generated from a private key and is used to encrypt data.

2:Encryption and digital signatures.

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#4235

1.Public key is an open key you can share with everybody, you need a private key to open the data on the public key.

2.Encryption and Digital signatures

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#4236
  1. They are pair of keys that are used to encrypt and decrypt a message. Private key is only known to the person who is encrypting the message and should be kept safe and Public key is used to decrypt and is accessible by everyone.
  2. Real estate transaction, Health related documents, Legal Documents.
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#4237

1. Describe the concept of public and private key with your own words.
Private Key - a large random number that is generated fot the specific person, not to share with anyone, also, cant be regenerated, if its lost, its lost.

Public Key - a larger number derived from the private key, this number can be shared anywhere, when someone uses the public key to encrypt a message only the private key that this specific public key is derived from can be used to decrypt that message.

2. What 2 use-cases can public key cryptography be used for?
The first use case is that a public key cryptography is used to create a bitcoin wallet address.
The second use case is that public key cryptography can be used to decrypt messages when its intended to be private and to be sent / read by a specific person.

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#4238

These would be use cases for digital signatures which can be made using the private key. The other use case you mentioned in the first answer, which is encryption. :slight_smile:

#4239

  1. Private key is known and shared only by me. It is useful to unlock a public key. But a public key cannot be reverse engineered to discover a private key.

  2. Public keys can be used for digital signatures, or for sending info…does anyone read this homework??? If so I will put effort into it. Do I need validation? Ivan do you read this lol

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#4240
  1. Public key (can be seen by everyone) is generated by a private key (keep it secret!)
  2. For encryption and digital signatures
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#4241

  1. Describe the concept of public and private key with your own words.
    In cryptocurrencies you do not hava a central entity to keep track of all wallets instead each wallet is based on a public and private key. The public and private keys are a pair. The public key is derved from the private key.

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

  1. Encryption- you can receive messages that are encrypted with your public key and you can decrypt them with your private key.
  2. Digital Signatures- are used in cryptocurrencies. Mostly in bitcoin. When sending a transaction your private key signs the transactions for others to see. Its a way for others to identify a message.
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#4242

1.Public key is an code which anyone can see but without private key it is meaningless.Private key should not be shared by anyone and it is to unlock the detail of public key.
2. Encryption and Digital signature.

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#4243

Yes of course we are reading, it is good to put effort into it.

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#4244

  1. The concept of public and private keys are to safely and securely send messages on a public platform without the risk of it being discovered or hacked.

  2. Public key cryptography can be used for ENCRYPTION and DIGITAL SIGNATURES.

– Encryption isn’t really used for Cryptocurrencies, but it’s a way to safely send a message without anyone being able to read it.

– Digital Signatures are used for Cryptocurrencies and it’s a way to verify a particular sent message.

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#4245

  1. Public and private keys are like your own digital signature-- that uniquely identifies you as the owner. Private key is randomly generated by your computer while public key is derived from the private key.
    Public key is an identifier that can be shared with the public.

  2. Sample Use Case 1: Encryption
    Sample Use Case 2: Digital Signatures

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#4246

Thank you Maki…now I need to redo some homework haha.

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