> For the complete documentation index, see [llms.txt](https://wiki.songer.pro/interviewing/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://wiki.songer.pro/interviewing/security-domains-and-technical-aptitude/cryptographic-protections/cryptography/what-is-cryptography.md).

# What is cryptography?

Cryptography is the practice and study of techniques used to secure communication in the presence of third parties called adversaries. It involves the use of codes and ciphers to protect sensitive information, such as personal information, business secrets, and military data. Cryptography is used to protect data in transit, such as through the internet, and to store it securely.