A public key (public key) is one of the main elements of asymmetric cryptography, on which the security of the blockchain is built. It is a long alphanumeric string and, unlike the private key, is not secret: it can be openly shared with other network participants.
The public and private keys always form a linked mathematical pair. The private key is kept secret and used to sign transactions, while the public one allows that signature to be verified and confirms that the disposal of funds really comes from the owner. At the same time, it is practically impossible to compute the private key from the public one — this is what the reliability of the system rests on.
The public key and the wallet address
In practice, to receive funds it is more common to use not the public key itself but the wallet address, which is formed from it through hashing. The address is a shorter and more convenient representation that can be safely shared with the sender. Disclosing the public key or address does not threaten the safety of the assets, whereas the loss or compromise of the private key leads to a complete loss of control over the funds.
