birthday attack

Birthday attack, also known as Birthday paradox, is a cyber attack defined by its capacity to exploit the mathematics behind the birthday paradox problem. It is based off of a theorem first postulated by mathematician Richard Von Mises in the early 1900s. The basic formula implies that, with a given set of numbers, there is a greater chance of two of these numbers having the same birthday (i.e. month and day) than for two of them to have different birthdays. This theorem has been further established in statistical probability. The concept has since been used to illustrate diversity and unpredictability of probability in a variety of areas, such as cryptography.

In cryptography, the birthday attack is a method of attacking encoding codes or ciphers by exploiting the fact that they will eventually produce the same codeword given the same input. Using the birthday paradox, a malicious actor can find this codeword in a relatively short amount of time. Additionally, a birthday attack only requires the attacker to know that the code or cipher is based on a birthday or date, as well as the length or size of the cycle (number of possible birthdays). As such, it is assumed that the birthday attack is general enough to successfully target any cipher.

The birthday attack finds its vulnerability due to the heightened probability of getting two of the same outputs at a given time, as opposed to two different ones. This probability shrinks significantly with the more randomness added to a system. Such randomness can be achieved by using a variable length encryption algorithm. This means that the amount of information encrypted varies with each input, limiting the efficiency of the attack from being able to guess what the code may be.

In addition to variable length encryption algorithms, there are several other methods to combat the problems associated with a birthday attack, such as “birthday oracles” or birthday “puddles”. A birthday oracle is designed to find the birthday of a given input by calculating all possible combinations of inputs and outputs. This technique renders the attack useless if system is not susceptible to the attack, as the birthday oracle can immediately detect any input that is attempting to exploit the system.

The birthday “puddle” approach is another cause of combating the attack, but this technique is often used as a last resort. With a puddle approach, the system produces a list of outputs which are generated from random inputs. This list is monitored to find any patterns which could indicate a birthday attack. If a pattern is detected, it is immediately corrected by randomly replacing the previous inputs and outputs with new ones, totally randomizing the system.

In conclusion, the birthday attack is a powerful attack, but it can be prevented and rendered ineffective. Using variable length encryption algorithms and other solutions, like birthday oracles or birthday puddles, security measures can be implemented to greatly reduce the chances of a successful attack on a secure system.

Birthday attack is a general attack method used against the cryptographic hash functions. It is a type of brute-force attack that exploits the birthday paradox. The basic idea behind this is that it takes fewer attempts to find a collision than expected by trying random inputs.

The attack is named after the birthday paradox, as the number of trials needed to find a collision is approximately equal to the square root of pi. This means that in a large enough collection of hashes, it is likely that several will end with the same final output, or a collision.

The attack works by taking a large number of inputs, hashing each one, and then comparing them for any duplicates. If a duplicate is found, then it is thought that the two inputs had the same start value and the same end value. The attack can then be used to create a malicious file with the same end value as a legitimate file, allowing the attacker to bypass any security protections such as digital signatures.

In order to prevent a birthday attack, a cryptographer may choose to use a longer hash, or a more secure hashing algorithm. It is also important to use a salt value during hashing which adds an extra layer of security. This makes it much more difficult to find the same hash value for different inputs, making the attack much more difficult to execute.