Encryption
Encryption is the process of changing data into a secret code using a algorithm (cipher).[1] It is usually carried out today by computers, although in the past it was traditionally carried out by analog machines or by specialists known as cryptographers.
History
The earliest known form of encryption is that known as "ROT-13," or the "Caesar cipher", because its invention was once reportedly attributed to Julius Caesar.[2] In the Caesar cipher, each letter of the message (or "plaintext") is shifted forward in the alphabet by 13 places; for example, "CIPHER" becomes "PVCURE".[3] The Caesar cipher is what is called a symmetric cipher, meaning that the method of encryption is the same as the method of decryption (rotate by 13 characters), and therefore it is just as easy to decode any message as it was to encode it. For this reason, modern cryptanalysts tend to view most symmetric encryption methods as flawed.[4]
Another popular historical encryption method was the "enigma machine" developed by Nazi Germany during World War II. The enigma machine (or ENIGMA for short) worked on the plugboard principle. It had the ability to generate many different ciphertexts for the same plaintext using different "keys", which meant that Allied cryptographers could no longer rely on being able to match encoded texts with plaintexts. Prior to World War II, cryptographers had gotten used to being able to collate messages with their ciphertexts to create large "dictionaries" (for example, matching the ciphertext "PVCURE" with its plaintext "CIPHER" in the above example). These code dictionaries could then be used to launch dictionary attacks against messages whose decodings were not yet known. ENIGMA rendered this tactic hopeless. For example, while "PVCURE" might mean "CIPHER" using Monday's key, it might mean "ATTACK" using Tuesday's key. However, a letter cannot be encrypted as itself, so no key can decrypt "PVCURE" as "POISON".
The Enigma cipher was first cracked by three Polish mathematicians: Marian Rejewski, Jerzy Rozycki, and Henryk Zygalski.[5] Despite this, filmmakers have tried to give the credit to British mathematician Alan Turing, who was taught by the Polish experts how to build a computer to continue to decipher the Enigma.
The deciphering of the Enigma was the beginning of modern cryptography as a science, although few advancements were made from the end of WWII until the rise of the Internet in the 1980s.
Modern usage
Encryption is used heavily on the internet today, since it is the only practical way to prevent interception of valuable information by hostile parties in this environment. More than half of the websites across the internet now utilize HTTPS, which encrypts web traffic between hosts and clients using TLS.[6] Additionally, progress is being made towards encrypting DNS traffic, which has historically been transmitted in the clear, using TLS as well.[7]
Encryption is also sometimes used to create secure VPN "tunnels" for internet traffic. Businesses sometimes utilize this to protect their confidential information as it moves from remote locations (such as laptops, phones, and cloud providers) to their internal network, or vice versa. This VPN tunnel can give hints to hostile parties as to what may be going on, but it prevents them from simply intercepting and reading the information being communicated.
Encryption in also used extensively in cloud environments, where there are typically no physical security controls available to the cloud customer (other than the service provider's own protections). The industry standard is for data to be encrypted "at rest" (while being stored) and "in motion" (while being communicated from one point to another).[8] Data is also sometimes encrypted "in use" (while being processed by one or more CPUs).[9]
Several forms of "strong" encryption have been considered munitions under US federal law, the exportation of such encrytion to belligerent countries such as Iran has been restriced.[10]
Harmful uses
Like any tool, encryption can be used for good or evil. Encryption is sometimes used by hackers and other anti-government types to conceal their activities from the federal government. For example, the leftist GNU organization provides a program called "Pretty Good Privacy" (PGP) for encrypting e-mail; this can have legitimate uses, but is also sometimes used for concealing underhanded communication.
Encryption is also used by some malware, to conceal the malicious payload and avoid security scanners. Ransomware takes a different approach, by encrypting personal or corporate files on infected computers, then demanding a ransom payment before (possibly) disclosing the decryption key.
See also
References
- ↑ http://www.webopedia.com/TERM/E/encryption.html
- ↑ Far more likely, however, is that the Caesar cipher was invented by a mathematician in Caesar's employ, and Caesar merely took the credit, much as Henry VIII took credit for the melody of "Greensleeves", or President James Garfield claimed to have discovered a novel proof of the Pythagorean Theorem.
- ↑ The lack of the letters "J", "Q", "U", and "W" in the Latin alphabet posed an impediment to the Caesar shift's widespread adoption, since the encoded ciphertext would actually have read "PVCVRE" and thus had four different possible decodings.
- ↑ http://www.centurionsoft.com/centurionmail/wpencryption.html
- ↑ https://www.telegraph.co.uk/science/2016/03/15/polish-codebreakers-cracked-enigma-before-alan-turing/
- ↑ https://www.wired.com/2017/01/half-web-now-encrypted-makes-everyone-safer/
- ↑ https://developers.cloudflare.com/1.1.1.1/dns-over-https/
- ↑ https://csrc.nist.gov/publications/detail/sp/800-53/rev-4/final
- ↑ https://www.datamotion.com/best_practices_-securing_data_at_rest_in-use_and_in_motion/
- ↑ "Encryption Export Controls" at stanford.edu