Encryption: The process of making information unintelligible
There are many ways to make information unintelligible; you could use a foreign language, you could write it backwards, you could use a proprietary file format, etc. However, these methods simply mask information by keeping secret whatever method was used. Once the method is discovered, then it is relatively easy to unmask the information.
Encryption is successful because it utilizes computing strength and speed to transform the information by both rearrangement and the interjection of new data, not simply obscuring it. There is no need to keep the method secret, as the actual process is not what makes encryption strong enough to resist attack. The strength relies on the attacker not knowing what order and what new data has been used during the transformation. The decryption becomes practically impossible by generating vast ranges of possible combinations that would require years of brute force guessing to break.
Encryption is accomplished by using algorithms and functions to perform mathematical operations on the information. The three basic cryptographic methods used to protect information are cryptographic hash functions, asymmetric-key algorithms, and symmetric-key algorithms.
Cryptographic Hash Function: a Unique Subsection of Encryption
Hash functions accept any amount of plaintext as input, which generates a fixed-length ciphertext output. The output is called a hash value, sometimes known as the digest or checksum. The hash value can act as a type of signature, ensuring the contents of a message or file have not been modified. This is done by comparing the hash value of the message generated before transmission to the hash value generated after transmission. If the values match, then the message has not been modified.
While not a true encryption algorithm, hash functions can be used as a type of one-way encryption method. We will use a very simplified method as an example. Let us take any length number and add its digits together until you arrive at a single digit. If you take the number 1985 and add the digits together, you would get 1 + 9 + 8 + 5 = 23, followed by 2 + 3 = 5. Using this method, 1985 = 5, 100003 = 4, and 12345 = 6. Regardless of how many digits we input, we always end up with the same size output. It is a one-way process since there is no way of reversing the function to arrive at the original number. In the example above, the hash-value of “5” could have originated from many sets of numbers.
Other than cryptographic hash functions, other basic cryptographic methods used to protect information are asymmetric-key algorithms and symmetric-key algorithms. Learn more about Cryptographic Methodologies >>