Homework on Public and Private Keys - Questions

Blockchain and Bitcoin 101
#3162
  1. Private Keys are the root to all things you and need to be kept private like a government ID number. Private keys are used for encryption, decryption, signing and in the future even more. Public keys are things everyone can see but are derived from your private keys using a hash function.
  2. a. Encryption of messages and subsequently decryption of messages
    b. Digital Signatures stating that you sent a message/transaction.
1 Like
#3163

Public keys are derived using the Elliptic curve function, not a hash function like SHA256. :slight_smile:

#3164

  1. A private key is something created by the user and only for the user. This key then crates a public “key” that acts more or less like a lock. This lock can only be opened by the private key. When a message is locked with that public key and sent to the user only he can view the contents of the message. This is the basis of encryption.

  2. The first case in which a public key can be used is to send a secure message to another person that may or may not include highly sensitive information; however, the second use for such key can be to enable transactions much like a hash. This is in the sense of only the person who sends and receives the information will be able to use it. If i were to send the payment to somebody via their public key, then there is no way for a person to steal that information, thus making it a highly secure method of communication.

1 Like
#3165
  1. Describe the concept of public and private key with your own words.

A Private key is a random number generated belonging to an individual, and is used to digitally sign that the transaction/message is from the owner of the private key, kind of like a password that only the owner knows. A public key is a number generated from the private key and is used to add security and to enable transactions/messages, and can be seen by everyone. A private key cannot be worked out from a public key.

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

Two uses are encrypted messages and data sharing/transactions digital signatures

1 Like
#3166
  1. Describe the concept of public and private key with your own words.

Privet key is created in your machine for you and public key is derived from that private key

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

To sign and to send or receive crypto

1 Like
#3167

Transactions utilize digital signatures to function. Public key cryptography can also be used for encryption. :slight_smile:

#3168

  1. Describe the concept of public and private key with your own words.
    The public key is generated from the private and the private key can’t be generated from the public key.

  2. What 2 use-cases can public key cryptography be used for?
    Case 1 - Encryption cryptography.
    Case 2 - Digital signature cryptography.

1 Like
#3169

  1. Private key is generated line of code which stands , for example, for our digital wallet.It is unique and should be keep secret as anyone who knows it can access a wallet. Then from that line of code public key is generated which was bitcoin address back in the days. Now another step of security is added so the bitcoin address is generated form public key.

  2. It can be use to send encrypted messages. It’s generate bitcoin address.

1 Like
#3170

The address is now a hash of the public key, but it was not really implemented because of security but mostly to save on storage. Public key is 65 bytes and a hashed address is 20 bytes :slight_smile:

Generating addresses is not really a use case, its the signing of messages (transactions) - digital signatures.

1 Like
#3171

Thanks for that :slightly_smiling_face:

#3172

  1. a private key can generate a public key but not the other way around. It is therefore useful for encryption, where only the people knowing the private key can unlock the message, and useful for digital signatures, were a private key sent with the message can be verified to correspond to a persons public address.

  2. the two use cases is in encryption and digital signatures

1 Like
#3173

  1. Public and private keys are one of the things that put the crypto in cryptocurrency. Its essential because it allows security in exchanging over a completely open network by utilizing the one directional quality of SHA-256 in the private and public key relationship as well as the private key and digital signature relationship.

  2. The 2 main use cases are for encryption and digital signatures are the 2 main cases but there are potential adaptations such as in tracking packages

1 Like
#3174

SHA256 is not used in PK cryptography, to derive public keys the Elliptic curve function is used. :slight_smile:

1 Like
#3175

1: Private key is for generating unique public key and share it on unsecured network, who ever whats tu send you private message has to use his own private key with your public key to create message nobody but will able to read it.
2: 1–Encryption, for example sending encrypted emails
2-- Digital signature, for proofing that it was me who sent it

1 Like
#3176

Hello,

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

Public key is your public address or your unique “known” footprint. Private key is a unique “unknown and secret footprint” that mathematically can be linked to your public key for source verification. This is possible because the private key, which is a randomly generated number, is used to generate the public key.

A message signed with your private key can be verified as yours using your public key.

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

Encryption - A public key can be used to encrypt a message and its corresponding private key will decrypt it.
Digital signatures – As stated in the 1st question, the source of a message that has been signed with a private key can be verified by using its corresponding public key.

R

1 Like
#3177
  1. Describe the concept of public and private key with your own words. Private key is random number created as a kind of an ID of a factor in crypto ecosystem. It is visible only to the owner of the private key. Public key is a mathematical derivation of a private key that can be visible publicly. Private to Public key is only one way function. Reverse is impossible.
  2. What 2 use-cases can public key cryptography be used for? Encryption and digital signature.
1 Like
#3178

  1. The private key is a random large number generated by a computer, hashing this number generate another large number, that is the public key. This public key can be shared and is always linked with his privat key, but is impossible to reverse due to the property of the hash function.

  2. There are this 2 use-cases
    *Encryption: I can use a public key to ensure the encryption before sending a message. Only if the receivers have the original private key which have generated the public key i have used to encrypt, they can decrypt the message.
    *Digital Signature: I can send a message (not encrypted) with a signature which is generated from my privat key. If the receivers know my public key they can mathematically veirify if my signature is generated from my privat key without know that. And this enable full authentication of sender, for example in Bitcoin, we dont have an account with a wallet linked. Bu only a couple of public and privat key used to veirfy all the transaction we are involved. In bitcoin if you lose your privat key, you lose your coin.

1 Like
#3179

Homework Public/Private Keys 1/17/21

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

Public key is shared with others, a private key is not. Both are necessary in the usage of a digital wallet. My wallet address is a product of both a public and my private key. Public key encrypts information, a private key decrypts said information.

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

Encryption and digital signatures

1 Like
#3180

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

Computer generate a random number; these numbers are called private key.

Public key can be used by public and can also be known by public which helps to receive cryptocurrency and don’t have to worry about its privacy.

But on the other hand, private key is your key to protect from everyone. As the rule of the thumb Your Private key Your Coin. Anybody knows your private key has your coin.

Following certain function public key is generated through private key.

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

1) In encryption: The sender combines the public key of receiver with the secret 			message, encrypt it in the public network. 

2) Digital signature: Sender’s digital signature (which is generated by private 	     key of sender) and sender’s public key work together, in order to verify the                   transaction.
1 Like
#3181
  1. Describe the concept of public and private key with your own words.
  • The concept of public key is a key that can be seen and share with everyone, the private key is a random key generated by a computer which is personal cannot be share to anyone.
  1. What 2 use-cases can public key cryptography be used for?
    • Encryption
    • Digital signature
1 Like