# cryptography

/kɹɪptˈɒɡɹəfi/ (UK) · CEFR C1 · Noun

Source: https://englishreference.com/word/cryptography
Updated: 2026-07-22

## Definition

the study or practice of writing and solving secret codes. It is used to keep information safe so that only the right people can read it.

For teachers: the science or practice of transforming information into a secure format to prevent unauthorised access. It involves the use of mathematical algorithms to encrypt and decrypt data.

## Examples

- Modern banking relies on cryptography to keep your money safe.
- The government uses advanced cryptography to protect sensitive communications from being intercepted by foreign agencies.
- While classical cryptography focused on simple letter substitution, modern digital systems employ complex prime number factorisation to ensure the integrity of global financial transactions.

## Usage notes

- Uncountable in its general sense as a field of study or a practice.

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