Cryptanalysis is the converse process of Cryptography. Cryptography is science and art of making the message secret, where as Cryptanalysis is the art of cracking the codes and breaking the security. The person who performs the Cryptanalysis is known as the Cryptanalyst. The Cryptanalyst’s job is to decode the secrets either by hook or crook, he keeps on trying different combinations. The performance of a Cryptanalyst depends upon the time he/she takes to decode the data. It means that the lesser the time a Cryptanalyst takes; the better is his/her performance.
In Cryptanalysis, the Cryptanalysts firstly analyze the data and try those combinations which they feel are the most probable ones, if that does not comes off then they start on trying all possible combinations. The task of a Cryptanalyst is hit and trial based. The trying of combinations of a Cryptanalyst is termed as an attack. The trying of every possible combination by a Cryptanalyst is known as brute force attack. The methods like transposition, substitution etc., are very vulnerable to Cryptanalyst’s attacks as they can be broken in a matter of seconds. Other methods like DES (Data encryption standards), Diffie-hellman which involve a very complex key are hard to break.
Most of the Cryptography methods baring some like AES, Diffie-hellman etc., can be broken by the Cryptanalysts but the time constraint is also very important. For example, a Cryptanalyst decoding the message after the whole processing regarding that message has been done, is of no use. So, good Cryptanalysis is achieved only when the message is decoded in time. There are various ways in which a Cryptanalyst can attack like:
Encrypted message attack: In this attack the Cryptanalyst has the copy of encrypted message available. This is the most common scenario as the encrypted message is relatively easy to obtain.
Chosen message attack: Here, some quantity of original message is available to the Cryptanalyst and then he/she tries to obtain the encrypted message.
Adaptive chosen message attack: It is a special case of chosen message attack. Here the Cryptanalyst obtains the some part of the original message dynamically.
Chosen encrypted message attack: In this case the Cryptanalyst obtains a part of the encrypted text from which he/she tries to obtain original message.
Adaptive chosen encrypted message attack: It is a special case of the previous attack; here the Cryptanalyst obtains the Encrypted text dynamically.
by Camila 1 year ago
Relevant Links