Private Key
In the context of cryptocurrencies and blockchain technology, a private key is a crucial component of a cryptographic system that enables an individual to access and control their digital assets. It is a secret, alphanumeric string that serves as a kind of password or digital signature.
Cryptographic systems, including those used in cryptocurrencies like Bitcoin or Ethereum, use a pair of keys: a public key and a private key. These keys are mathematically related, but while the public key can be shared openly, the private key must be kept confidential.
The public key is derived from the private key and is used to generate a public address. This public address is shared with others when a user wants to receive cryptocurrencies. It's like sharing your bank account number for someone to send you money.
The private key, on the other hand, must be kept secret. It's used to sign transactions and prove wallet ownership. In some instances, the user can be in possession of their private key (in the case of a self-hosted wallet owner), or a tertiary party (VASP) may hold the key (in the case of a custodial wallet owner).