Describe cryptography
The desire to keep secrets has been with us since we first learned to communicate. As we developed new methods and ways of communicating over the centuries, the need to share secrets with friends and allies grew.
Definition of cryptography
Cryptography, derived from the Greek word "Kryptos", which means hidden or secret, is the application of secure communication in any form between a sender and a recipient. Typically, cryptography is used to obscure the meaning of a written message, but it can also be applied to images.
The first known use of cryptography can be traced back to ancient Egypt and the use of complex hieroglyphics. One of the first ciphers ever used to secure military communications came from the Roman Emperor Julius Caesar.
These two examples make clear that cryptography has many uses and isn't limited to the digital world. However, from those humble origins, one thing is sure, cryptography is now a fundamental requirement in helping secure our digitally connected planet.
- Each time you use a browser to access, for example, an HTTPS address, an online retail store, your bank, or even this Learn site, elements of cryptography are keeping your interactions confidential and secure.
- Whenever you wirelessly connect a device to a router to access the internet, cryptography helps make it secure.
- You can use it to secure and protect files on external or internal storage.
- Smartphones have changed the way we communicate, from video and audio calls to text messaging. Cryptography is used to maintain the confidentiality and integrity of these communications.
As with all systems, cryptography has its own language of terms and phrases. Two of the important ones are plaintext and ciphertext.
- The term plaintext represents any message including documents, music, pictures, movies, data, and computer programs, waiting to be cryptographically transformed.
- When the plaintext has been turned into a secret message, it's called ciphertext. This term represents the encrypted/secured data.