Sunday, 25 May 2014

Know more about PASSWORDS

Know more about PASSWORDS


Passwords are keys that control access. They let you in and keep
others out. They provide information control (passwords on documents);
access control (passwords to web pages)
and authentication (proving that you are who you say you are).

Types of Passwords

There are three main types of passwords.

Strings of Characters

At the most basic level, passwords are stings of characters, numbers
and symbols. Access to a keyboard or keypad allows entry of these
types of passwords. These passwords range from the simplest – such as
the three digit codes used on some garage door openers – to the more
complicated combinations of characters, numbers and symbols that are
recommended for
protecting highly confidential information.

Strings of Characters plus a token

The next level in passwords is to require a string of characters,
numbers and symbols plus a token of some type. An example of this is
the ATM, which requires a card - the token - plus a personal
identification number or PIN. This is considered more secure, because
if you lack either item, you are denied access.

Biometric Passwords

The third level in passwords is the biometric password. This is the
use of non-reproducible biological features, such as fingerprints or
facial features to allow access. An example of this is the retinal
scan, in which the retina – which is the interior surface of the back
of the eye – is photographed. The retina contains a unique pattern of
blood vessels that are easily seen and this pattern is compared to a
reference. Biometric passwords are the most sophisticated and are
considered 'safer' but in reality a password that you 'carry' in your
finger or eye is no safer than a strong password that you carry in
your head, provided that the software that uses the password is
correctly configured.

History of Passwords

In older versions of MS Excel and Word, passwords were stored as plain
text in the document header information. View the header and you could
read the password. This is valid for all versions older than Office

Windows once stored passwords as plain text in a hidden file. Forget
your password? You could just delete the hidden file, and the password
was erased.

Early on, Microsoft and Adobe both used passwords to mean that a file
was password
protected when opened with their applications. If you opened it with
another application,
such as Notepad, the password wasn't necessary.

Microsoft Access 2.0 databases could be opened as a text file easily
by just renaming them
with a ".txt" extension. Doing this allowed you to see the database data.
Adobe PDF files in versions 4.0 and older were printable and often
viewable using Linux PDF readers or Ghostview for Windows.

Wireless networks have a problem with encryption as the key for the
encryption can be
guessed once you collect enough encrypted data out of the air to find
the patterns and
guess the keys. With todays computing power in the normal home, the
key can be cracked almost immediately to find the password.

Bluetooth security is considered very secure, once it is setup. The
problem is that bluetooth transmits a unique, freshly generated,
password between the devices to establish the connection and the
password is sent as plain text. If that password is intercepted, all
future transmissions for that session can be easily decoded.

Build a Strong Password

The best passwords:

? cannot be found in a dictionary

? contain numbers, letters and those odd swear symbols on top of the numbers

? contain upper and lower case letters

? the longer the "stronger"

With a 2 letter password, and 26 letters in the alphabet, plus 10
numbers (ignoring symbols), there are 236 possible combinations
(687,000,000 possibilities). Increase the password length to 8
characters, and there are 836 combinations
(324,000,000,000,000,000,000,000,000,000,000 possibilities).

There are many password generators available on the internet, but
these will generate a
nearly impossible to remember password.

Try instead to use a seemingly random string of letters or numbers
that you can easily recall.

For example:
gandt3b! (goldilocks and the 3 bears!)
JJPL2c1d (john, jill, paul, lucy, 2 cats, 1 d – the members of your household)

Password Encryption

People don't usually discuss password encryption, because there seems
to be no options to discuss – passwords are, by definition, encrypted.
While this is usually true, encryption is not a simple yes or no
proposition. The effectiveness of encryption, usually described as its
strength, ranges from very weak to extremely robust.
At its weakest, we have passwords that have been simply encoded. This
produces a password that is not readable directly, but, given the key,
we could easily translate it using a computer, pen and paper, or a
plastic decoder ring from a cereal box. An example of this is the
ROT13 cypher.

ROT13 replaces every letter in a text with the letter that is 13
places away from it in the alphabet. For example 'ABC' becomes 'NOP'.
Even when using algorithms that can more accurately be called
encryption, the encryption is weak, if the key used to generate it is
weak. Using ROT13 as an example, if you consider the 13 place
differential to be the key, then ROT13 has an extremely weak key.
ROT13 can be strengthened by using a different key. You could use
ROT10, replacing each letter with the one ten places forward, or you
could use ROT-2, replacing each letter with the one two places before
it. You could strengthen it even more, by varying the differential,
such as ROTpi, where the first letter is shifted 3 places; the second,
1 place; the third, 4 places; the fourth, 1 place; and so on, using pi
(3.14159265...) to provide a constantly varying differential.

Because of these possible variations, when you are encrypting any type
of information, you must be sure that you are using a reliable method
of encryption and that the key – your contribution to the encryption –
will provide you with a robust result.
You must also remember that a good system of encryption is useless
without good passwords, just as good passwords are useless without
good encryption.

Password Cracking (Password Recovery)

Password cracking for illegal purposes is illegal. But if it is your
password, then it's your
information. Once you password protect something, and then forget your
password, you are stuck. Hence password recovery.

Password cracking consists of a few basic techniques
"Looking around": passwords are often taped to the bottom of
keyboards, under mousepads, posted on personal bulletin boards.
Brute force: just keep trying passwords until one works
Automated dictionary attacks: these programs run through a series of
possible dictionary
words until one works as a password.
There are many programs available on the web to assist with password recovery on
documents. However, newer versions of programs are becoming more and
more secure, and therefore, more and more difficult to obtain
passwords using the techniques above, or using password recovery

Protection from Password Cracking

Here are some suggestions on how to keep your passwords from being cracked:

1. Use strong passwords that cannot be determined by a dictionary attack.

2. Don't post your passwords near your computer.

3.Limit wrong attempts to three tries, then lock the account. The
password must then be reset.

(This does not apply to documents or password protected zip files –
they do not have lock out

4.Change passwords regularly.

5. Use a variety of passwords for different computers. Does this mean
that you need to create a unique password for everything? Absolutely
not. Maintain a master password for things that don't matter to you
(perhaps the account you were required to create for or
for your account on the local newspaper). But use good passwords for
anything that actually needs to be secure.

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