cryptography

American  

[krip-tog-ruh-fee] / krɪpˈtɒg rə fi /

noun

1. the science or study of the techniques of secret writing, especially code and cipher systems, methods, and the like.

2. the procedures, processes, methods, etc., of making and using secret writing, as codes or ciphers.

3. Computers.

   1. the study or process of using algorithms to scramble or hide data, validate messages and digital signatures, etc., in order to secure digital information against unauthorized access or corruption.

      Cryptography has been rapidly evolving to introduce more hacker-proof algorithms.

   2. an instance of this.

      The application’s cryptography provides a strong element of security, but is unlikely to be proof against all cyber threats.

4. anything written in a secret code, cipher, or the like.

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cryptography British  

/ krɪpˈtɒlədʒɪ, ˌkrɪptəˈɡræfɪk, krɪpˈtɒɡrəfɪ /

noun

1. the science or study of analysing and deciphering codes, ciphers, etc; cryptanalysis

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cryptography Cultural  

1. The science of coding and decoding messages so as to keep these messages secure. Coding (see encryption) takes place using a key that ideally is known only by the sender and intended recipient of the message.

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Discover More

Historically used in warfare, cryptography is now used routinely in computer networks. This often pits the desire of individuals and businesses to keep Internet information private against the need of government to investigate crime and terrorism.

Other Word Forms

• cryptographal adjective
• cryptographer noun
• cryptographic adjective
• cryptographical adjective
• cryptographically adverb
• cryptographist noun

Etymology

Origin of cryptography

First recorded in 1635–45; crypto- + -graphy

Compare meaning

How does cryptography compare to similar and commonly confused words? Explore the most common comparisons:

• cryptology vs. cryptography

Explanation

Cryptography is the art or science of decoding coded messages. Even if you intercept a note from one of your siblings to the other, it's going to require cryptography to decipher it. When you practice cryptography, you're an expert at both composing and unraveling messages that are written in some kind of code to ensure their privacy. In the old days, cryptography meant translating text into illegible nonsense that could only be understood by the recipient, and then decoding it using a code key or instructions. Today, most cryptography involves supercomputers and math. The Greek roots are kryptos, "hidden," and graphia, "writing."

Example Sentences

Google specifically is pushing for a transition to post-quantum cryptography, or the use of new, quantum-resistant algorithms to secure data against future attacks.

From Barron's • Apr. 1, 2026

Charles H Bennett and Gilles Brassard's work, which dates back to 1984, is known as quantum cryptography and has "redefined secure communication and computing", the award's body said.

From BBC • Mar. 18, 2026

Now, the real question: What happens when quantum computers can break elliptic curve cryptography?

From MarketWatch • Dec. 28, 2025

Researchers expect major breakthroughs in physics, medical research, cryptography and several other fields as these machines mature.

From Science Daily • Dec. 1, 2025

Most of the papers dealt “with the history of cryptography and should belong to the American people,” he argued.

From "The Woman All Spies Fear" by Amy Butler Greenfield