Watch out to those pubic keys 
(Sorry, I was reading other peopleās answers to check how I did, yours was only a few answers away before mine, and I often have the sense of humor of a ten year old boy).
Helloā¦I use Metemask. Is my public address the one scene on Etherscan? And is my private key the one with the password phrase? Do you verify a transaction address sent to you by tracing the address on Etherscan? And regarding the encrypted messages sent between Bob and Alice in the beginning of video, what kind of encrypted messaging? Sorryā¦old school gmail messagesā¦lol. Thank you
Yes I think public keys are the same as the address in Ethereum. In Bitcoin this is not the case because the address is a hash of the public key.
Metamask uses a BIP32 compatible HD (hierarchical deterministic) wallet with a mnemonic phraze (the 12 or 24 words defined in BIP39) which are used to derive private keys so you only need to back up these words to be able to recover your wallet.
Well if your old school you have probably heard of the Enigma machine 
encryption is simply a method of sending secure messages between two parties in an insecure connection. HTTPS (not HTTP) uses PK cryptography to encrypt messages between server and client like for example when you visit Gmail. 
Thank youā¦much appreciated. Rico
1.-Public key is for anyone to see and can be used for encryption and digital signatures (identification) and it is derived from the private key. There is a mathematical relationship between the two keys, in which anyone can use the private key to encrypt a message but only the private key will be able to decrypt it.
2.-2 use cases for public key are: Encryption and Digital signatures
1 Like
I correct my answer#1
1.-Public key is for anyone to see and can be used for encryption and digital signatures (identification) and it is derived from the private key. There is a mathematical relationship between the two keys, in which anyone can use the PUBLIC key to encrypt a message but only the private key will be able to decrypt it.
2.-2 use cases for public key are: Encryption and Digital signatures
1 Like
Thank you for your contribution! 
1 Like
1)private key interacts with your public key private key used as a signature for a transaction to be verified
2)verification of a transaction
1 Like
-
Public key is for sending messages. Everyone has access to the public keys. The only way to decrypt
the message sent through the public key is by having the matching private key. Only the owner of the public key should have access to the private key. -
One use is encryptions. So random they can not be broken, this is useful for sending messages or money.
When someone uses their private key to send a message through another persons public key, the private key of the sender acts as a digital fingerprint
1 Like
1.) A private key is random number is created by a computer for use of someone for digital signatures or other cryptographies. The public key is generated from the private key for others for communications or transfers of data from the private key to the public key.
2.) digital signatures and encryptions
1 Like
- For every public key there is only one private key that matches. With the matching public and private key, messages are able to be encrypted and decrypted. (i.e., Bob and Alice each have the public and private key that match. Bob has a message for Alice so he encrypts the message with the public key. Alice is then able to decrypt the message with the private key. She is also able to send the message back to Bob with the same method, by encrypting her response with the public key and Bob will be able to decrypt with the private key.)
- (i) Digital signatures allow developers to confirm a message was provided by a trusted identity.
(ii) Sealing API will allow information to be stored on a database. By sealing the API, information can be encrypted with the public key and store the private key. When the time comes to revisit the information, private key can decrypt the information.
1 Like
1.) the concept of public and private key adds a high layer of security to the network. each private key generates a public key that now can be shared with anyone. that public key also generates the BTC address. since it is not possible to go from bitcoin address to private key or from public key to private key, since it is a one way function it is safe to share public keys and addresses. enabling you to share your addresses with strangers and doing transactions on the blockchain.
2.) the public key cryptography there for can be used for 2 major use cases. first, encrypting a msg / transaction that only the receipting party can unpack and read. secondly, as a signature that verifies the sender as the true sender. both use cases create a trustless environment in which i know, that only i can decrypt a message send to me and i know exactly who it was coming from.
however if someone gets another persons private key they can act on someone elses behalf. sending funds or messages pretending to be someone else.
KEEP YOUR PRIVATE KEY SAFE AND HIDDEN FROM ANYONE!
1 Like
Both of these would utilize digital signatures. The other use case for PK cryptography would be encryption.
1.Public key are generated from the private key , but you cannot derive the private key from the private key. The private key signs messages sent and is mathematically compared to the public keys to verify the sender.
2.It can be used to encrypt messages and digital signatures
1 Like
1private key is randomly generated number and the public key is a type of hash from that
2public key cryptography can be used to verify a sender and receiver of a message
1 Like
-
Public and private keys are ways to encrypt a message in an arena that is public. A private key is a random generation of numbers that only the individual who has created has access to. From this, the public key is derived which is able to be seen by anybody without compromising the security of the private key. This is because of the hash function used, which makes it impossible to go from an output (public key) to an input (private key).
-
The 2 use cases are for encryption and for digital signatures. Encryption is used when sending messages which should be kept private in a public place. Digital signatures are a way to confirm that the message was sent by the right person and not an imposter. This works by āsigningā a message with the private key, and sending it through the public key.
1 Like
1. Describe the concept of public and private key with your own words: your private key is like your private folder where you can read or listen to messages/data. The public key is your public identity to receive data and is a way for others to identify you. The public key is generated from your private key which takes data received publicly and reads it in private. Each cryptocurrency wallet whether on exchange or hardware will generate a private key where it identifies where you will hold your cryptocurrency.Which is essential you keep it secure.
2. What 2 use-cases can public key cryptography be used for? The public key generates a BTC or other cryptocurrency wallet address that broadcast it online while protecting the content of your wallet blocked via the private key. This is how the BTC is transparent yet secure. With your private key you gain access to your funds in order to send BTC to others or to transfer your BTC to another exchange or hardware wallet.
1 Like
-
A private key is a number that only you know. The public key is generated from the private key and can be seen by anyone. You can use the private key to unlock messages sent to the public key but you can never access the private key with just the public key. The public key is your unique address and the private key is your secure way to access the information held within that public key address.
-
2 use cases for public - private key pairs are Digital signatures and encryption.
1 Like
- Describe the concept of public and private key with your own words.
A. A private key is your personal key which is used to decrypt messages sent to your public key. Your private key can also be used as a signature to confirm that you are the sender. Your public key is available for all to see. - What 2 use-cases can public key cryptography be used for?
A. The uses are for identification and verification of sender which could be for emails or sending payments.
1 Like
-
Private key is a random generated number only held by the individual who generated it.
There will be used equation on the random generated number to become a public key. -
digital signatures are used to verify who sent the message since the private key derives the public key.
The public key creates the BTC-adress.
1 Like