Whenever a set of data is to be encrypted, the people involved, develop an algorithm, that outlines the steps that need to be taken in order to first encipher, and then decipher this data. The cryptographic algorithm is not shared with the general public, unless the technique itself, is to be taught across the world.
If the cryptographic technique is meant for the company only, the algorithm is only shared with the people involved with the content in question, after a non disclosure has been signed, to prevent further spread of the algorithm.
One one end, the concerned personnel follow the steps to encipher the desired data, while on the receiving end, they use the algorithm to decipher the encrypted data that has been received.
Example of usage – “He developed his own cryptographic technique, and chose not to share the algorithm with anyone, other than his closest of friends.”