Encryption
To understand what a brute force attack is, we must first understand the technology that is designed to attack. This technology that I speak of is data encryption. Data Encryption is used to protect code and other information from prying eyes by changing the data based upon keys, which are essentially complicated, lengthy passwords. To obtain access to the data it is necessary to have the key, otherwise the information is rendered useless.
Motive
It is in the interest of some parties, such as hackers, law enforcement, intelligence agencies, etc, to break this encryption and gain access to the data contained within. Brute force attacks are one method used to discover the key needed to unlock the data. It is by far the most rudimentary cracking process, involving trying every combination possible. Imagine forgetting a friend’s phone number and starting at 100 – 0000. And since guessing the right number gets exponentially harder every time a new number set is introduced it could take years to do even for the fastest dialer. In the same way computer systems, hardware or software, attempting to crack a key are limited by power, heat and other variables, as described in the laws of thermodynamics, making extremely long keys impractical to crack.
Entropy
However, a lot of attacks are inherently easier as some may have already noticed from the example above. If you really were to forget a phone number you would know based upon certain outside variables such as country, state, county, city, etc, that many choices can be eliminated. Many numbers can be considered either completely impossible or at the very least, very improbable. As you get more exact with your friend’s lost number the less random choices you would need to make to guess the correctly. This once daunting number starts to seem a little tamer. Certain outside factors such as pressure and temperature can affect a computer systems ability to choose numbers in a random way. This slight leveling of Einstein’s playing field, made possible by the study of entropy, enables brute force attacks to crack keys that seem to be statistically impossible.
Breakdown
Ultimately, using the right encryption combined with the technology available today, brute force attacks are on the loosing team. They are simply unable to tackle the insurmountable mountain of number combinations made available by modern encryption technology. Even advanced hardware designed specifically for the task ultimately will fail when matched with against current encryption methods. So, don’t forget your key inside one of these monsters, the lock smith won’t be much help.
Here all you want to know symmetric encryption and asymmetric encryption, the fundamental types of encryption schemes. This article also features stream ciphers, blocks ciphers and, for instance, sheds a light on Public Key Cryptography.
An encryption algorithm is mathematical operation where plaintext is transformed to so called ciphertext, unintelligible to anyone who doesn’t know the secret key to decrypt it. Encryption algorithms have their roots in the Greek history, and until the advent of computing have encrypted messages been the domain of the military and erudites. These days encryption is also used for secure online banking, digital rights management, protecting health data and email exchange such as by PGP for example.
Encryption algorithms are called symmetric when the same secret, password or key is used to encrypt and to decrypt. Shared secret algorithms either operate on a bit bases (stream ciphers) or encrypt chunk of bites (block ciphers). Encryption algorithms which use a different key for decryption and encryption are called asymmetric and have some functional advantages over symmetric encryption which if fast, and can be secured by on-the-fly key generation and frequent key changes.
The downside of symmetric encryption is that anyone who knows the secret key or password can transform the secret cipher text to plaintext. This makes symmetric encryption vulnerable to leaking, and spying out passwords. A famous example of symmetric encryption used to be DES (Data Encryption Standard) which is no longer in wide use. DES and its variants have now largely been replaced with Advanced Encryption Standard (AES) which uses a 128, 192, or 256 bit key. The longer the key the more secure the message is in general (“theoretically stronger”).
Asymmetric encryption on the other hand employs a different key for decryption and encryptions by so called public key encryption in which anyone can get the public key of the recipient to encrypt files or messages so that only the holder of the private key of the public-private key pair can open the item. In a similar operation can the holder of the private key sign messages so that anyone can check message authenticity. RSA ( Rivest, Shamir and Adleman) is the de-facto standard algorithm public key encryption algorithm. The downside of public key encryption is that asymmetric encryption usually is much slower and needs more computing power than shared secret encryption.
When have been discussing types of encryption in terms of symmetry, which is common. Another way to classify encryption algorithms is differentiating in secure and non-secure encryption. Secure encryption algorithms are those whose inner workings have been made known to the public such as, for example AES whilst until recently perhaps no-one has discovered a flaw in the algorithm or was able to break it (In contrast are secret encryption schemes usually considered not to be secure. Rather, people speak of security through obscurity). save money at fast cash