-: Password Hacking :-
Password cracking is the process of recovering
secret passwords from data that has been stored in or transmitted
by a computer system. A common approach is to repeatedly try guesses
for the password.
Most passwords can be cracked by using following techniques :
1) Hashing :-
Here we will refer to the one way function (which may be either an
encryption function or cryptographic hash) employed as a hash and
its output as a hashed password.
If a system uses a reversible function to obscure stored passwords,
exploiting that weakness can recover even 'well-chosen' passwords.
One example is the LM hash that Microsoft Windows uses by default
to store user passwords that are less than 15 characters in length.
LM hash breaks the password into two 7-character fields which are
then hashed separately, allowing each half to be attacked separately.
 | Hash functions like SHA-512,
SHA-1, and MD5 are considered impossible to invert when used correctly. |
2) Guessing :- Many passwords
can be guessed either by humans or by sophisticated cracking programs
armed with dictionaries (dictionary based) and the user's personal
information.
Not surprisingly, many users choose weak passwords, usually one
related to themselves in some way. Repeated research over some 40
years has demonstrated that around 40% of user-chosen passwords
are readily guessable by programs. Examples of insecure choices
include:
* blank (none)
* the word "password", "passcode", "admin"
and their derivatives
* the user's name or login name
* the name of their significant other or another person (loved one)
* their birthplace or date of birth
* a pet's name
* a dictionary word in any language
* automobile licence plate number
* a row of letters from a standard keyboard layout (eg, the qwerty
keyboard -- qwerty itself, asdf, or qwertyuiop)
* a simple modification of one of the preceding, such as suffixing
a digit or reversing the order of the letters.
and so on....
In one survery of MySpace passwords which had been phished, 3.8
percent of passwords were a single word found in a dictionary, and
another 12 percent were a word plus a final digit; two-thirds of
the time that digit was.
|
A password containing both uppercase &
lowercase characters, numbers and special characters
too; is a strong password and can never
be guessed. |
3) Default Passwords
:- A moderately high number of local
and online applications have inbuilt default passwords that have
been configured by programmers during development stages of software.
There are lots of applications running on the internet on which
default passwords are enabled. So, it is quite easy for an attacker
to enter default password and gain access to sensitive information.
A list containing default passwords of some of the most popular
applications is available on the internet.
|
Always disable or change the
applications' (both online and offline) default username-password
pairs. |
4) Brute Force :-
If all other techniques failed, then attackers uses brute force
password cracking technique. Here an automatic tool is used which
tries all possible combinations of available keys on the keyboard.
As soon as correct password is reached it displays on the screen.This
techniques takes extremely long time to complete, but password will
surely cracked.
|
Long is the password, large
is the time taken to brute force it. |
5) Phishing :-
This is the most effective and easily executable password cracking
technique which is generally used to crack the passwords of e-mail
accounts, and all those accounts where secret information or sensitive
personal information is stored by user such as social networking
websites, matrimonial websites, etc.
Phishing is a technique in which the attacker creates the fake login screen
and send it to the victim, hoping that the victim gets fooled into entering
the account username and password. As soon as victim click on "enter"
or "login" login button this information reaches to the attacker
using scripts or online form processors while the user(victim) is redirected
to home page of e-mail service provider.
|
Never give reply to the
messages which are demanding for your username-password,
urging to be e-mail service provider. |
It is possible to try to obtain the passwords
through other different methods, such as social engineering, wiretapping,
keystroke logging, login spoofing, dumpster diving, phishing, shoulder
surfing, timing attack, acoustic cryptanalysis, using a Trojan Horse
or virus, identity management system attacks (such as abuse of Self-service
password reset) and compromising host security.
However, cracking usually designates a guessing attack.
By definition cryptography is the process of converting recognisable data into
an encrypted code for transmitting it over a network (either trusted or
untrusted). Data is encrypted at the source, i.e. sender's end and decrypted
at the destination, i.e. receiver's end.
