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What Is Encryption? (with pictures) – wiseGEEK: clear …

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Encryption refers to algorithmic schemes that encode plain text into non-readable form or cyphertext, providing privacy. The receiver of the encrypted text uses a "key" to decrypt the message, returning it to its original plain text form. The key is the trigger mechanism to the algorithm.

Until the advent of the Internet, encryption was rarely used by the public, but was largely a military tool. Today, with online marketing, banking, healthcare and other services, even the average householder is much more aware of it.

Web browsers will encrypt text automatically when connected to a secure server, evidenced by an address beginning with https. The server decrypts the text upon its arrival, but as the information travels between computers, interception of the transmission will not be fruitful to anyone "listening in." They would only see unreadable gibberish.

There are many types of encryption and not all of them are reliable. The same computer power that yields strong encryption can be used to break weak schemes. Initially, 64-bit encryption was thought to be quite strong, but today 128-bit is the standard, and this will undoubtedly change again in the future.

Though browsers automatically encrypt information when connected to a secure website, many people choose to use encryption in their email correspondence as well. This can easily be accomplished with programs that feature plug-ins or interfaces for popular email clients. The most longstanding of these is called PGP (Pretty Good Privacy), a humble name for very strong military-grade encryption program. PGP allows one to not only encrypt email messages, but personal files and folders as well.

Encryption can also be applied to an entire volume or drive. To use the drive, it is "mounted" using a special decryption key. In this state the drive can be used and read normally. When finished, the drive is dismounted and returns to an encrypted state, unreadable by interlopers, Trojan horses, spyware or snoops. Some people choose to keep financial programs or other sensitive data on encrypted drives.

Encryption schemes are categorized as being symmetric or asymmetric. Symmetric key algorithms such as Blowfish, AES and DES, work with a single, prearranged key that is shared between sender and receiver. This key both encrypts and decrypts text. In asymmetric encryption schemes, such as RSA and Diffie-Hellman, the scheme creates a "key pair" for the user: a public key and a private key. The public key can be published online for senders to use to encrypt text that will be sent to the owner of the public key. Once encrypted, the cyphertext cannot be decrypted except by the one who holds the private key of that key pair. This algorithm is based around the two keys working in conjunction with each other. Asymmetric encryption is considered one step more secure than symmetric encryption, because the decryption key can be kept private.

Strong encryption makes data private, but not necessarily secure. To be secure, the recipient of the data often a server must be positively identified as being the approved party. This is usually accomplished online using digital signatures or certificates.

As more people realize the open nature of the Internet, email and instant messaging, encryption will undoubtedly become more popular. Without it, information passed on the Internet is not only available for virtually anyone to snag and read, but is often stored for years on servers that can change hands or become compromised in any number of ways. For all of these reasons, it is a goal worth pursuing.

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What Is Encryption? (with pictures) - wiseGEEK: clear ...

Google says Gmail encrypted

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Google says its popular Gmail service will use encryption to thwart snooping, in the latest move by the tech sector reassuring customers following revelations about US surveillance programs.

'Your email is important to you and making sure it stays safe and always available is important to us,' said Gmail engineering security chief Nicolas Lidzborski on Thursday in a blog post.

'Starting today, Gmail will always use an encrypted HTTPS connection when you check or send email.. Today's change means that no one can listen in on your messages as they go back and forth between you and Gmail's servers -- no matter if you're using public WiFi or logging in from your computer, phone or tablet.'

Google has already begun scrambling most of the traffic at its websites as technology firms grapple with moves by US intelligence agencies to spy on what people are doing and sharing online.

Similar moves have been announced by Yahoo, Microsoft and Facebook to use encryption that limits the ability of a third party to read messages or emails.

US tech firms have been ramping up encryption since last year's explosive revelations about the vast surveillance capabilities of the National Security Agency (NSA) and other intelligence services, based on leaked documents.

Lidzborski said Google's latest move 'ensures that your messages are safe, not only when they move between you and Gmail's servers, but also as they move between Google's data centres - something we made a top priority after last summer's revelations.'

Some reports say the NSA had been able to access data centres of Google and other web firms.

Experts say encryption generally prevents outsiders from intercepting a person's messages or documents, but that a persistent effort can gain access through malware or other methods which trick a person into revealing passwords.

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Google says Gmail encrypted

Is Linux Mint the best distro to replace Windows XP?

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March 31, 2014, 11:37 AM Windows XP users are in a tough situation as that operating system draws close to its end of life. But there are many alternatives to Windows XP, and ZDNet thinks that Linux Mint might a very good one indeed.

I get it though. You know XP like the back of your hand and Windows 8.x has left you as cold as a penguin in the Antarctica ocean. You may also have considered switching to a Mac and gotten hives from just the thought, or contemplated a Chromebook but couldn't get past the idea of relying so much on the Internet and Software-as-a-Service (SaaS). I suggest an alternative you may not have considered: Linux Mint.

Yes, I'm serious, and not just because I tend to use Linux desktops a lot and Mint in particular. I'm suggesting it for XP users for several specific reasons.

More at ZDNet

Image credit: ZDNet

There's also a gallery of Linux Mint and Windows XP images that show some similarities between the two desktop environments.

A basic primer on open source software Sci-Tech Today has a useful primer on the basics of open source software. It could be helpful if you ever need to explain to someone what open source means.

Open source software is software that is freely distributed. In other words, it is software that is free to acquire. Everyone can access it and modify the code if they wish. The opposite of open source is proprietary software that is closely held and controlled.

For example, Microsoft Office is proprietary software. Most open source software is community based, meaning many developers in different places work independently on the software. Open source may sound really "techie" oriented (and it is), but you may be surprised to find open source software all around you and how much it is affecting innovation.

More at Sci-Tech Today

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Is Linux Mint the best distro to replace Windows XP?

An Overview of Cryptography – GaryKessler.net Home Page

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Does increased security provide comfort to paranoid people? Or does security provide some very basic protections that we are naive to believe that we don't need? During this time when the Internet provides essential communication between tens of millions of people and is being increasingly used as a tool for commerce, security becomes a tremendously important issue to deal with.

There are many aspects to security and many applications, ranging from secure commerce and payments to private communications and protecting passwords. One essential aspect for secure communications is that of cryptography, which is the focus of this chapter. But it is important to note that while cryptography is necessary for secure communications, it is not by itself sufficient. The reader is advised, then, that the topics covered in this chapter only describe the first of many steps necessary for better security in any number of situations.

This paper has two major purposes. The first is to define some of the terms and concepts behind basic cryptographic methods, and to offer a way to compare the myriad cryptographic schemes in use today. The second is to provide some real examples of cryptography in use today.

I would like to say at the outset that this paper is very focused on terms, concepts, and schemes in current use and is not a treatise of the whole field. No mention is made here about pre-computerized crypto schemes, the difference between a substitution and transposition cipher, cryptanalysis, or other history. Interested readers should check out some of the books in the references section below for detailed and interesting! background information.

Cryptography is the science of writing in secret code and is an ancient art; the first documented use of cryptography in writing dates back to circa 1900 B.C. when an Egyptian scribe used non-standard hieroglyphs in an inscription. Some experts argue that cryptography appeared spontaneously sometime after writing was invented, with applications ranging from diplomatic missives to war-time battle plans. It is no surprise, then, that new forms of cryptography came soon after the widespread development of computer communications. In data and telecommunications, cryptography is necessary when communicating over any untrusted medium, which includes just about any network, particularly the Internet.

Within the context of any application-to-application communication, there are some specific security requirements, including:

Cryptography, then, not only protects data from theft or alteration, but can also be used for user authentication. There are, in general, three types of cryptographic schemes typically used to accomplish these goals: secret key (or symmetric) cryptography, public-key (or asymmetric) cryptography, and hash functions, each of which is described below. In all cases, the initial unencrypted data is referred to as plaintext. It is encrypted into ciphertext, which will in turn (usually) be decrypted into usable plaintext.

In many of the descriptions below, two communicating parties will be referred to as Alice and Bob; this is the common nomenclature in the crypto field and literature to make it easier to identify the communicating parties. If there is a third or fourth party to the communication, they will be referred to as Carol and Dave. Mallory is a malicious party, Eve is an eavesdropper, and Trent is a trusted third party.

There are several ways of classifying cryptographic algorithms. For purposes of this paper, they will be categorized based on the number of keys that are employed for encryption and decryption, and further defined by their application and use. The three types of algorithms that will be discussed are (Figure 1):

With secret key cryptography, a single key is used for both encryption and decryption. As shown in Figure 1A, the sender uses the key (or some set of rules) to encrypt the plaintext and sends the ciphertext to the receiver. The receiver applies the same key (or ruleset) to decrypt the message and recover the plaintext. Because a single key is used for both functions, secret key cryptography is also called symmetric encryption.

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An Overview of Cryptography - GaryKessler.net Home Page


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