The algorithm used to generate public and private keys which are the unique codes essential to cryptocurrency transactions. If the same password is used to encrypt and decrypt something, this is called a symmetric key algorithm. In that instance both the sender and the receiver have the same key. Each can encrypt and exchange information privately. However since both parties have the decoding information, they cannot keep information private from one another. With an asymmetric key algorithm, two different passwords are created. Anything encrypted with one can be decrypted by the other. In practice, one is selected to be a private key , and kept secret. The other is designated a public key and broadcast to the public at large. Both parties have access to the public key, but only the person with the private key can decode the encryption. This ensures that only that person can access the funds.
Malone, J.A (2015). Glossary of Bitcoin Terms and Definitions. United States: Lulu Press, Inc