Password attack, Brute-force attack, Dictionary attack and Birthday attack

Password attack:

Because passwords are the most commonly used mechanism to authenticate users to an information system, obtaining passwords is a common and effective attack approach.

Access to a person’s password can be obtained by looking around the person’s desk, sniffing the connection to the network to acquire unencrypted passwords, using social engineering,

gaining access to a password database or outright guessing.

Brute-force attack:

It is like using a random approach by trying different passwords

and hoping that one work some logic can be applied by trying passwords related to the person’s name, job title, hobbies or similar items.

Dictionary attack:

It is used to attempt to gain access to a users computer and network. One approach is to copy an encrypted file that contains the passwords, apply the same encryption to a dictionary of commonly used passwords, and compare the results.

Birthday attack:

These are made against a hash algorithm that is used to verify the integrity of a message, software or digital signature. A message processed by a hash function produces a message digest (MD) of fixed length, independent of the length of the input message. This birthday attack refers to the probability of finding two random messages that generate the same message digest when processed by a hash function. If an attacker calculates same message digest for his message as the user has, he can safely replace the user’s message with this, and the receiver will not be able to detect the replacement even if he compares message digest.