Homework on Public and Private Keys - Questions

Blockchain and Bitcoin 101
#5068

And the second use case is digital signature(verifying that you’re the one who sent a message.)

#5069

  1. Describe the concept of public and private key with your own words.?
    Public and Private key is used to encrypt and decrypt data on an open network. Every participant in the network will have two keys public and private key. Public key is made public and everyone knows it but private key must be kept secure. for e.g A wants to send messsage to B and wants that no one else can read that message other than B. So what A will do is A will encrypt the message with B’s public key and will send the message. The B can decrypt the message with his private key and can read the message.

  2. What 2 use-cases can public key cryptography be used for?
    The two use cases where public key cryptography can be used are
    a. To send message securely between two persons. By encrypting message through publice key and decrypting it by using private key.
    b. To verify and authenticate whether message was sent by the same person who claims it to send. Digital signature comes into play here.

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#5070

  1. private key: a unique number generated by your computer that is only for you.
    public key: a number that comes from your private key and is visible for everyone.

  2. encryption & digital signature

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#5071
  1. a private key is a randomly generated number and from that, a public key is derived. The public key will be the same generated number from the private key due to the hashing, but you cannot get the private key from the public key.
  2. Encryption and digital signatures
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#5072

  1. Public and Private keys are a randomly generated set of numbers created by your computer which helps keep track transactions or messages and who they were sent by, as bitcoin doesn’t have any kind of centralized entity to keep track of all that. In addition, A private key will automatically generate a public key.

    1. Encryption: By having the public key of a user, we can send encrypted messages to that user with our public key which will be decrypted by their private key.
    2. Digital Signatures: When a user sends bitcoin to another bitcoin address, they must first use their private key to sign the transaction and then have the public key prove that the digital signature was made by that private key, to make it known by the nodes that they sent this bitcoin.
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#5073

  1. Private key is a randomly generated sequence of numbers that is unique to that user and not to be shared with anyone. Public key is derived from that private key and thus forever associated with it and is a way to verify that transactions or signatures are coming from the private key without anyone knowing the actual private key sequence.

  2. PublicPrivate Cryptography is used for encryption of messages and also for digital signatures

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#5074

  1. Describe the concept of public and private key with your own words.
    A public key is used to encrypt messages.
    A private key can generate a public key but a public key can’t find out or generate a private key.
    If you loose your private key you are dead.

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

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#5075
  1. Private key is a randomly generated large number by your computer and is kept secret. The public key is essentially a hash function output generated from the input of the private key.
  2. Public keys can be used to encrypt messages that only the holder of the correlating private key can open. Public and private keys are also used in crypto wallets where the private key is used for digital signatures in the verification process and the public key is used to complete transactions with other users.
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#5076

A private key is a randomly generated large number which is then mathematically processed in to a public key. The private key cannot be derived from the public key, but anything encrypted by the public key can only be decrypted by the private key, and the public key will not be able to decrypt this.

Cryptocurrency and public key signing digital documents or encrypted email PGP.

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#5077

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

The public key :key: is the key which everyone can see.

The private key :key: is a randomly generated number which is transformed into the public key
(The private key should only you have and know and It should be kept secretly)
Encryption can only be signed or decoded when you have the private key.

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

It can be used for digital signatures and encryption, to send funds or messages.

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#5078
  1. Describe the concept of public and private key with your own words.

This technique is used to send information securely over a computer network. The sender generates a private key from which a corresponding public key is automatically generated. With the public key anyone can encrypt data that only I can open with my private key.

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

Digital certificates prove the authenticity of participants in the Bitcoin network and ensure data integrity. Moreover, public key cryptography is also used to encrypt data.

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#5079

  1. Public/Private key technology is an important milestone in Computer Science. By key we understand basically something that can be represented with a number. A public key is a key that is derived from a private key by means of a hash function (a one-way function). Therefore, only a party that is in possession of the private key can (computationally / probabilistically / realistically) have produced that public key. Public keys are keys you can share publicly while private keys should be kept secret. Private keys are generated with a random number, and the Public key corresponding to that Private key is generated with a hash function.

  2. The two use-cases for public/private key cryptography are:

    a) Encryption - A wants to send a message to B. A wants to make sure no party other than B will be able to read the contents of that message. B sends the public key to A. In fact, B does not need to send the public key to A, basically what happens normally is that B safely broadcasts it’s public key to everyone in the internet. A will use the public key to encrypt the message and send it to B. Once the encrypted message reaches B, B can use the private key to decrypt the message and read it. If someone other than B tries to read the message, they will only see gibberish.

    b) Signing - A wants to send a message to B, and wants to make sure that it was in fact A who wrote the message (proof of irrefutability). A can produce a hash of the message using the private key. Since the public key of A is publicly available, anyone can now take A’s key and check that the message was signed with A’s private key, meaning it was only computationally feasible for A to have ever signed that message. Signatures are used in Bitcoin to prove that Address A wanted in fact to send a certain amount of bitcoins to Address B, and A cannot deny it.

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#5080
  1. The public key is shared with others and makes it to where they can encrypt data that only your private key can decrypt. The private key is not shared with anyone.
  2. The 2 use cases are snding a message or sending a transaction.
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#5081

  1. The public key is derived from the private key which can decrypt messages encrypted by the public key. The public key can therefore be shared with the public so that they may send encrypted messages to you.

  2. They can be used for sending encrypted messages and digital signatures.

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#5082

  1. Public key is the hash function generated everyone can see. Private key, which actually generates your public key, is for your eyes only that can decrypt whatever data is sent to your public key.

  2. Encryption and digital signatures

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#5083
  1. In cryptography, a private key and a public key are interconnected! First, a private key (an extremely large and random number) is typically generated by a wallet program. Second, a public key is then mathematically derived from that private key. They are related to each other mathematically. You need BOTH keys to transact.

At this point, the private key can now be looked upon as a password; something that must NEVER be disclosed to anyone. On the flip side, the public key is meant to be shared with the world (similar to an email address you give someone). To receive or access cryptocurrency or a cryptographic message, you would first share your public address with the person that wants to send you a payment/message. In order to access those funds or message, you would then use your private keys as the recipient to “unlock” the cryptocurrency or message. Since you are the only one who knows the password, you will be the only one that will have access to it.

Keep in mind that the random generation of a “private key” and the subsequent derivation of a “public key” from that private key uses a one-way hash function. Moreover, it is also possible to generate multiple public address using algorithms that are also linked mathematically to both the original private and public keys using one-way hash-functions.

  1. The 2 use-cases for public key cryptography are:

i) Encryption(public key is to encrypt; and private key is to decrypt) and
ii) Digital Signatures (public key is used to verify signatures; and private key is to create digital signatures).

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#5084
  1. The private key is a randomly generated number that results in a public key. The private key cannot be derived from the public key. Together they allow for the encryption and verification of e.g. messages without exposing the private key of the sender.
  2. Encrypted messages and digital signatures
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#5085
  1. Private key is secret and it shouldn’t be shared with no1, based on that we are creating a public key that can be used for encrypting and the only person with a private key can decrypt it. It is also used for creating BTC addresses and creating a signature.
  2. Encryption and digital signatures.
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#5086
  1. Describe the concept of public and Private Keys in your own words.

Private keys are generated from a large random number. It should never be shared with anyone. The Public Key can be derived from the private key. The public key is the one that everyone sees/uses in transactions. The creation of the keys are unidirectional. Private Key —>> Public Key, but you can never go from Public Key —> Private Key. If you lose or have your Private Key stolen, you’ve lost your Crypto. “Not your Keys, not your crypto.”

  1. What 2 cases can public Key cryptography be used for?

Two use cases for Public Key cryptography are Identity and integrity. The Digital signature from your private key for the transaction will allow you to identify yourself as the sender/receiver/owner of the crypto and it ensures the integrity of the transaction.

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#5087
  1. Describe the concept of public and private key with your own words.

Private keys are generated with a corresponding public key. Public keys allow the sending of encrypted data and are available to shared publicly. Public keys cannot be used by anyone to derive the corresponding private key.

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

Encryption and digital signatures.

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