Homework on Public and Private Keys - Questions

  1. the private key is a secret number that you computer generates that is used as a digital signature. It is also used to create a public key that other people can see and use. But you can’t know what the private key is using the public key. it is a one way system no going back.

  2. sending private messages and digital signatures

  1. Public keys are can be used to send encrypted messages with your private key.

  2. Encrypted messages and digital signing.

  1. Private key is as the name implies, private to you. That is your signature in the blockchain. It should be private to you. You use your private keys to sign transactions. Anyone that has access to your private key has got access to your digital asset and money. Public keys are at the core of Cryptography created from Private Keys. The public can see your private key because it is public but they cannot access your account with it. Your bitcoin address which is what you can give out to receive funds is also public and is generated from the Public key. The private key creates the public key and the public key creates the address. At the early stage of bitcoin the public key also served as the address. Someone having your address or public key cannot take anything from your wallet. It’s only with your private key that you can send out from your wallet. No one can go from the public key to the private key, you can only go from the public key to public because it is a one way traffic. Anyone can see the public key. But upon encryption, the public key will not make meaning to anyone else except the person it is encrypted for. The encryption can only be decrypted with a private key.
  2. The 2 Use-cases that Public key cryptography can be used are Encryption (protect your information from public view) and Digital Signature for identification.
  1. A private key can generate a public key for others to interact with.

  2. For private messaging and data sharing.

1. Describe the concept of public and private key with your own words.
A private key is a randomly generated large number from which a public key is generated. The private key is kept secret and is used to sign messages or send cryptocurrencies. The public key is there to everyone to see and can be used to receive cryptocurrencies for example.
2. What 2 use-cases can public key cryptography be used for?
Encryption and digital signatures.

Public keys are used to send data, information or value in a secure manner to someone or to the blockchain by encryption
To read the data sent a private key is require which originally hashed the public key
This private key is used to reverse the encryption

Public keys cryptography can be used in sending public emails
And using digital signatures for identity of documents ie legal documents, drawings, photos

  1. Describe the concept of public and private key with your own words.
    Cryptography uses public and private key pairs. A private key is randomly generated by a user’s computer and is unique to them and must be kept private at all times. A public key is derived from that private key and is shared publicly to enable people to send you encrypted messages or verify your signature. It is impossible to derive someone’s private key from their public key.

  2. What 2 use-cases can public key cryptography be used for?
    a. Encryption - This aspect of cryptography allows party A to send party B a message that has been encrypted using party B’s public key. Only party B is able to decrypt the message by using their private key to do so.
    b. Digital signing - Cryptocurrencies require a digital wallet address in which to store funds/data. This address is derived from a user’s public key, which was itself derived from their private key. When a user makes a transaction from their wallet, the private key is used to digitally sign the transaction and recipients can verify the integrity of the signature based on the public address of the wallet. At no point is the private and public key exposed in this scenario.

  1. A bitcoin wallet basically is the private key, which is generated through a function. The public key is generated from the private key using a one-way function. Bitcoin can go one step further and generate an address from the public key with another one-way function. This adds another layer of security, because you can keep your public key private as well. So an entire bitcoin wallet will consist of the private key, the public key and the adress. All of the keys are practically unique, because the chances of generating the same key twice are lower than the universe collapsing (Ivan’s words, not mine). Should it ever happen, both will contain the same bitcoins.

  2. Public key cryptography can be used to either sign a message or encrypt a message. There is no way to derive the private key from a public key.

  1. Public and private keys are a unique pairing of two strings. The public key sends or receives (as in your address) and the private key decrypts/confirms/authorizes (as in your signature).

  2. Encryption and digital signature.

  1. A public key is safe to broadcast on the internet or wherever. It is derived from the private key and the address is derived from the public key. The private key is used for signatures (somehow) and is what anyone needs to own your bitcoin.

  2. signing transactions and verifying digital signatures.

  1. The concept of Private and Public key is to allow exchanges of information between two parties away from prying eyes. A randomly generated pair of keys ( private and public ) are used to encrypt and decrypt messages. The public key which is derived from a private key is given to anyone who wishes to send private information across the network which eventually the private key is used to de-crypt the encrypted messages.

  2. The 2 use-cases for public key cryptography is encryption and digital signature.

  1. The private key is a large random number that should be kept very safe since the public key is created from it with cryptography so it can be used in an open, insecure environment.

2.1 Encryption of messages and such for privacy.

2.2. Digital signature to verify identity.

  1. Public key is used to encrypt/sign data publicly while staying “anonymous” while private key is used to decrypt the data from the public key.
  2. One use case is Cryptocurrencies to allow funds to be transferred between people publicly and securely. Another use case is password authentication.

1,2- The concept of public and private key cryptography is simply a way two do two things which are, first Encryption in which the receiver’s public key encrypts the data or message or transaction etc… and then only the receiver’s private key can decrypt the data, message, transaction etc, hence the sender can encrypt the massage without knowing the public key which is like an email address in which no one can know the private key by knowing the public key which is like the password. Second Digital signatures, which is used to verify whether or if the one who sent the data, message, transaction etc… is the one who actually did without needing to know the private key by signing it with the private key.

  1. A Private Key is a large random number generated to secure your
    private information. It is for your eyes only and cannot be backtracked
    to the Public key that can be generated from it. The Public Key is
    something the world can see and it can also be used to encrypt messages

  2. A Private Key is a large random number one can use to generate
    a Public Key, encrypt messages and create digital signatures.

1.public key is available for everyone to see and is also used to encrypt data allowing others to decrypt the data useing there private key or vise versa but you cant figure out someones private key useing there public
2. 2 uses? a) for sending encrypted messages and b) for digital signatures

  1. Describe the concept of public and private key with your own words.
    On the bitcoin network, the owner or the private key can move the funds associated with that key. The one who owns the private key owns the coins. A public key is then generated from the private key. The public key is the address you can share with people for them to send you funds, or even send a message that can only be read by the owner of the private key associated with that public key.
  2. What 2 use-cases can public key cryptography be used for?
    It is used for encryption and digital signatures
  1. Public key (derived from private key( is for every one to see and make use of in order to send an encrypted message or a transaction. Private key is my personal signature which can decrypt messages and puts a signature on transactions sent using the public key.

2 Encrypted messages. Transactions

1 Private key é um código alfanumérico, a public key é um código alfanumérico derivado da private key. A public key é utilizada como um endereço, para que outras public keys possam estabelecer comunicação.

No caso da criptografia, para manter a privacidade entre duas partes na transmissão de uma informação, a mensagem ou informação a ser comunicada é encriptada com a public key do receptor, essa mensagem a partir disso se torna irreconhecível e só poderá ser decriptada através da private key do receptor.

No caso da blockchain, ocorre a situação reversa. O mensageiro de uma informação utiliza sua private key para “assinar” uma informação e o receptor consegue checar a autenticidade da informação ao verificar a assinatura e a public key do mensageiro, constatando que somente a private key do mensageiro poderia ser utilizada para gerar a assinatura.

2 Criptografia para manter a privacidade entre mensageiro e receptor ou assinatura digital, para comprovar a autenticidade de uma informação.

  1. A public and private key is a pair of data that’s linked together and used to encrypt data sent between two parties.

  2. One use case could be secret messaging. When you’re on the internet, your ISP can see whatever data you are sending. But do they understand it? This is what public and private key cryptography solves; now you send encrypt the messages you send, and only the receiver will be able to decrypt the encrypted message (and then “understand” it). Another use case would be in cryptocurrency; to make sure that the unverified transactions sent into the blockchain was actually sent by the sender, and not another person.