Ask the Chatbot Games & Quizzes History & Society Science & Tech Biographies Animals & Nature Geography & Travel Arts & Culture ProCon Money Videos
cryptology
References & Edit History Related Topics
Images & Videos
A Vigenere cipher table displays the alphabet in both the top row and left column, with rows shifted to create a grid for encryption and decryption. Highlighted letters illustrate how to use the table. An explanation and example using the words cipher, key, and plaintext appears to the right. Letter frequency analysis of a Vigenère cipher Frequency distribution for plaintext and its repeated-key Vigenère cipher Diagram explaining the German ADFGVX cipher from World War I, showing a biliteral substitution array, examples of plaintext and intermediate ciphertext in red, and a transposition matrix with final ciphertext in blue. A circular cipher disk labeled Signal Corps U.S. Army, featuring two concentric rings of letters used for manual encryption by rotating the inner ring to align different alphabets. Enigma Hagelin M-209 U.S. cipher machine with its case open, showing exposed gears, rotors, and mechanical components used for encoding messages during World War II. Purple cipher machine Jade cipher machine
How William Friedman Tried to Prove That Francis Bacon Wrote Shakespeare's Plays
Quizzes
A botanical illustration from the Voynich manuscript, a codex, scientific or magical text in an unidentified language, in cipher; end of the 15th or during the 16th century (?).
Codes, Secrets, and Ciphers Quiz
Related Questions
Feedback
Corrections? Updates? Omissions? Let us know if you have suggestions to improve this article (requires login).
Thank you for your feedback

Our editors will review what you’ve submitted and determine whether to revise the article.

External Websites
A Vigenere cipher table displays the alphabet in both the top row and left column, with rows shifted to create a grid for encryption and decryption. Highlighted letters illustrate how to use the table. An explanation and example using the words cipher, key, and plaintext appears to the right.
Vigenère table In encrypting plaintext, the cipher letter is found at the intersection of the column headed by the plaintext letter and the row indexed by the key letter. To decrypt ciphertext, the plaintext letter is found at the head of the column determined by the intersection of the diagonal containing the cipher letter and the row containing the key letter.

cryptology

science
Written by
Gustavus J. Simmons
Former Senior Fellow, National Security Studies, Sandia National Laboratories, Albuquerque, New Mexico; Manager, Applied Mathematics Department, 1971–87. Researcher in command and control of nuclear weapons....
Gustavus J. Simmons
Fact-checked by
Britannica Editors
Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree....
Britannica Editors
History

cryptology, science concerned with data communication and storage in secure and usually secret form. It encompasses both cryptography and cryptanalysis. The term cryptology is derived from the Greek kryptós (“hidden”) and lógos (“word”). Security obtains from legitimate users being able to transform information by virtue of a secret key or keys—i.e., information known only to them. The resulting cipher, although generally inscrutable and not forgeable without the secret key, can be decrypted by anyone knowing...

Discover the world with Britannica

Subscribe to Continue Reading

Free Trial | No Ads | Exclusive Content
Explore Subscriptions
DNA
Right
Mobile