What does encrypting do?

Question

What does encrypting do?

Answer 1

Encrypting helps you hide (scramble) the content of a file by using certain algorithm. It then generates a public and private key which must be put together else the content will not be decrypted.



I will give a simple example on an algorithm using a zip compression software. When you zip a file, what you are sort of doing is using and encrypting software to scramble the content. The zip program has a dictionary of words/combination and replacements. For example every time it sees "EI" (2bytes) for example (recEIve), it replaces EI with 1 or 2 (1 byte) (jdepending on when it finds it). It also looks for word redundancies. See an example i got from how stuff work.



"Ask not what your country can do for you -- ask what you can do for your country."



The quote has 17 words, made up of 61 letters, 16 spaces, one dash and one period. If each letter, space or punctuation mark takes up one unit of memory, we get a total file size of 79 units. To get the file size down, we need to look for redundancies.



Immediately, we notice that:



* "ask" appears two times

* "what" appears two times

* "your" appears two times

* "country" appears two times

* "can" appears two times

* "do" appears two times

* "for" appears two times

* "you" appears two times



it pits these words in a new index and replaces the words with it. so ask (3bytes) become 1(1 byte), same with other words. then your sentence becomes "1 not 2 3 4 5 6 7 8 -- 1 2 8 5 6 7 3 4".



I bring zip up to make you understand the power of algorithms and index creation. A similar process goes on with encryption. So zip generally works by pattern recognition and word replacement. See http://computer.howstuffworks.com/file-compression2.htm for the full gist.



Encryption as you might have guessed works in a similar way but unlike a zip file, the dictionary is pre-defined. Eg. A=C, B=D, C=E you get). Unlike zip file which carry the dictionary along with the zip for re-construction, the encrypted file is sent without the dictionary. The receiver has the exact dictionary (a private key) and reconstructs the message when it arives. the key is usually more complex than that. with 128 bit encryption, each character is represented by a combination of 16 characters (i think) A=BCDE.... We need to confirm that though. When you encrypt a message, you build the private key on the fly so that it is different from another private key. Then you run your message through it and patterns are replaced. That is the general idea. I am sure you are wondering how you the key is sent. I suggest some more research. I also did not talk about the public key part of the equation. Still some more research.



I hope this helps.

Answer 2

encryption manipulates data to protect the contents from others reading that data without authentication.

Answer 3

From wikipedia.com



In cryptography, encryption is the process of transforming information (referred to as plaintext) using an algorithm (called cipher) to make it unreadable to anyone except those possessing special knowledge, usually referred to as a key. The result of the process is encrypted information (in cryptography, referred to as ciphertext). In many contexts, the word encryption also implicitly refers to the reverse process, decryption (e.g. “software for encryption” can typically also perform decryption), to make the encrypted information readable again (i.e. to make it unencrypted).

Encryption has long been used by militaries and governments to facilitate secret communication. Encryption is now commonly used in protecting information within many kinds of civilian systems. For example, in 2007 the U.S. government reported that 71% of companies surveyed utilized encryption for some of their data in transit.[1] Encryption can be used to protect data "at rest", such as files on computers and storage devices (e.g. USB flash drives). In recent years there have been numerous reports of confidential data such as customers' personal records being exposed through loss or theft of laptops or backup drives. Encrypting such files at rest helps protect them should physical security measures fail. Digital rights management systems which prevent unauthorized use or reproduction of copyrighted material and protect software against reverse engineering (see also copy protection) are another somewhat different example of using encryption on data at rest.

Encryption is also used to protect data in transit, for example data being transferred via networks (e.g. the Internet, e-commerce), mobile telephones, wireless microphones, wireless intercom systems, Bluetooth devices and bank automatic teller machines. There have been numerous reports of data in transit being intercepted in recent years.[2] Encrypting data in transit also helps to secure it as it is often difficult to physically secure all access to networks.

Encryption, by itself, can protect the confidentiality of messages, but other techniques are still needed to protect the integrity and authenticity of a message; for example, verification of a message authentication code (MAC) or a digital signature. Standards and cryptographic software and hardware to perform encryption are widely available, but successfully using encryption to ensure security may be a challenging problem. A single slip-up in system design or execution can allow successful attacks. Sometimes an adversary can obtain unencrypted information without directly undoing the encryption. See, e.g., traffic analysis, TEMPEST, or Trojan horse.

One of the earliest public key encryption applications was called Pretty Good Privacy (PGP). It was written in 1991 by Phil Zimmermann and was purchased by Network Associates (now PGP Corporation) in 1997.

There are a number of reasons why an encryption product may not be suitable in all cases. First, e-mail must be digitally signed at the point it was created to provide non-repudiation for some legal purposes, otherwise the sender could argue that it was tampered with after it left their computer but before it was encrypted at a gateway. An encryption product may also not be practical when mobile users need to send e-mail from outside the corporate network.[3]