Encryption keys are used to protect the confidentiality of data by encrypting it so that only those with the corresponding decryption key can access and read it. There are different types of encryption keys, such as symmetric keys, asymmetric keys, and public-key cryptography.
The most common way to get an encryption key is through a generated algorithm based on a password or phrase. This type of encryption key is known as a symmetric key and uses one shared secret between two parties for both encryption and decryption. Symmetric algorithms tend to be faster than asymmetric ones but require both parties to share the same secret beforehand in order for it to work properly.
Another popular method of getting an encryption key is using public-key cryptography which utilizes two separate but mathematically related keys – one for encrypting/decrypting data (public) and another for verification (private). The private key must be kept secure while the public key can be freely distributed so that anyone who needs to send you encrypted information has access to your public key. Public-key algorithms also have the advantage that they do not require any pre-shared secrets in order for them to function correctly.
Finally, there are hybrid methods which combine elements from both symmetric and public-key cryptography in order to provide additional security benefits over either approach alone. Hybrid approaches typically involve generating a random session key which is then used with a symmetric algorithm along with some form of digital signature or authentication via a public-key cryptosystem in order to ensure integrity during transmission or storage of messages or files over networks such as the Internet.