I read about Asymmetric key cryptography like EG-ECC , RSA, ECDH. I understand the concept of mathematics to these algorithms. But I have wondered about the public key for sender and private key for recipient. In other words,
Any other user who wants to send an encrypted message can get the intended recipient's public key from a public directory. They use this key to encrypt the message, and they send it to the recipient. When the recipient gets the message, they decrypt it with their private key, How much is the length of the message here is it necessary to have the message length smaller or equal to the length of the public key or the message can be any length of random words, can be divided into more than one block in this case we will use the sender's public key more than one time. Is the process of generating keys occur in the process of block encryption or message (size greater than size key) encryption?