In a world where the internet is a necessity, encryption is crucial for the privacy and integrity of our data. In general, encryption is a cryptographic process that takes plaintext, readable data and turns it into something indecipherable. This is done using either a single key (symmetric encryption) or two different but related keys (asymmetric encryption) to, essentially, scramble or unscramble data shared between two parties.<\/p>\n\n\n\n
In an interview with Time<\/em> magazine, Apple Inc. CEO Tim Cook<\/a> emphasized the significance of encryption in our online transactions and shared how it protects us from being ripped off by criminals.<\/p>\n\n\n\n Of course, there are different types of encryption and many more types of algorithms. One of the most popular, by far, is the advanced encryption standard, or AES. But what is AES encryption and why is it so important in online communications?<\/p>\n\n\n\n AES is a type of symmetric encryption<\/a>, meaning that it uses a single key to both encrypt and decrypt data. (This differs from asymmetric encryption, which uses a public key to encrypt and a private key to decrypt data.) The advanced encryption standard is endorsed by National Institute of Standards and Technology (NIST) and is used by the government agencies and contractors to secure sensitive information from prying eyes.<\/p>\n\n\n\n At its core, cryptography is based on mathematical functions and calculations. The security of the algorithm is in direct proportion to the complexity of the calculations. AES is one of the most secure algorithms around and uses highly complex mathematical functions to encrypt data. Nevertheless, the AES algorithm is short, secure, and compatible with most hardware, software, and firmware.<\/p>\n\n\n\n Today, the AES algorithm is used all over the world in software, hardware, and firmware in all kinds of devices. It’s free to use for public or private enterprises, for commercial or non-commercial purposes.<\/p>\n\n\n\n It\u2019s available in different varieties based on the size of the encryption keys used:<\/p>\n\n\n\n So, what does all of this mean? Let\u2019s put it in a little perspective. According to NIST<\/a>: \u201cFor a 128-bit key size, there are approximately 340 undecillion (340 followed by 36 zeros) possible keys.\u201d AES-256 is an exceptionally strong algorithm and is considered quantum resistant algorithm \u2014 meaning that quantum computers won\u2019t be able to crack it in a practical amount of time to make quantum computing a threat to it.<\/p>\n\n\n\n AES is the most widely trusted encryption standard in the world. It\u2019s used to secure data in all kinds of public and private settings, including:<\/p>\n\n\n\n There are many reasons why AES is so popular, including:<\/p>\n\n\n\n The original data encryption standard (DES)<\/a> had serious limitations that made it vulnerable to brute force attacks. DES began to lose its footing as a secure algorithm and, in 1997, the NIST began looking for a more secure alternative. NIST wanted an algorithm that was more powerful than DES and Triple-DES, with longer keys for more security. This is where the advanced encryption standard came into play.<\/p>\n\n\n\n Whereas DES was mainly supported by special-purpose hardware, AES was to be implemented on all kinds of software and hardware. It also had to work on hardware with limited computational capacities like smart cards or IoT devices.<\/p>\n\n\n\n Some people mistrusted the DES algorithm, as the source code was not open. There were also rumors that the National Security Agency (NSA) had designed a backdoor in the algorithm to spy on users. Although NSA denied these allegations, trust was hard to recover. So, with AES, NIST wanted to involve the cyber community and the public from the start, hoping to win their trust. This process is one of the major reasons behind the widespread acceptance of AES.<\/p>\n\n\n\n NIST announced AES development in January 1997, putting out a call for proposals in September the same year. They received 15 viable proposals<\/a> from people around the world, including Australia, Belgium, the USA, South Africa, Japan, and Korea. These were announced at the first AES Candidate Conference<\/a> in August 1998.<\/p>\n\n\n\n The second AES Candidate Conference (AES2) was held in March 1999 to discuss the proposed algorithms. Based on expert analysis and comments received from the public in Round 1<\/a>, NIST selected the best five algorithms from the proposals.<\/a><\/p>\n\n\n\n In Round 2<\/a> comments were again sought from the general public and an online forum was held to discuss the five finalist algorithms. NIST used this forum to examine and discuss issues around the algorithms, from implementation problems to intellectual property issues.<\/p>\n\n\n\n AES3 was held with the developers of the five finalists in New York USA over two days in April 2000. Finally, on October 2, 2000, NIST declared the Rijndael cipher<\/a> as the new advanced encryption standard.<\/p>\n\n\n\n Details of the new AES were published as Federal Information Processing Standards Publication 197<\/a> (FIPS 197) on November 26, 2001. Subsequently, NIST began a cryptographic algorithm validation program (CAVP)<\/a> to test every component of the algorithm before its implementation.<\/p>\n\n\n\n NIST made a few alterations to the Rijndael algorithm, changing block sizes and key lengths. In the original Rijndael cipher, the block and the keys were of variable lengths ranging from 128 bits to 256 bits. Of course, Rijndael\u2019s authors Joan Daemen and Vincent Jijmen later expanded the variable key and block sizes<\/a> in the multiples of 32 bits, thereby expanding the list of key and block sizes to 128, 160, 192, 224, and 256.<\/p>\n\n\n\n However, AES has a fixed block size of 128 bits and has the varying key lengths of 128, 192, and 256 bits that we touched on earlier.<\/p>\n\n\n\n The difference between AES and DES extends beyond their respective security strengths. For example, AES is based on a substitution-permutation network. Just like its predecessor DES, AES is a block cipher, meaning it divides the plaintext into blocks before encrypting it. Additionally, like DES, AES is a symmetric cipher that uses the same keys to encrypt and decrypt the data. This is where the similarities between the two end and the differences between DES and AES<\/a> begin:<\/p>\n\n\n\n Let\u2019s briefly explore the process of how the advanced encryption standard works to scramble data. In a nutshell, AES encryption takes the plaintext input data and divides it into 128-bit chunks of data called blocks. A single cryptographic key is then used to generate different subkeys \u2014 sometimes called round keys because a separate subkey is used for each round of processing \u2014 that will be applied to the different chunks of data. This produces a ciphertext for that data block.<\/p>\n\n\n\n Each block of ciphertext is then added onto the next until, finally, the final ciphertext is created that is the same size as the initial input data.<\/p>\n\n\n\n Depending on the size of the key used, the data will go through 10, 12 or 14 rounds of processing. It\u2019s also important to note that no two round keys are similar. Moreover, as the AES encryption doesn\u2019t use an initial vector; one additional key is generated for encryption at the beginning.<\/p>\n\n\n\n Here’s a great video that walks you through how the AES encryption process works:<\/p>\n\n\n\nWhat Is AES Encryption? An AES Definition and Explanation<\/h2>\n\n\n\n
AES Encryption Keys Come In Multiple Sizes to Offer Varying Levels of Security<\/h3>\n\n\n\n
Where Is AES Used?<\/h2>\n\n\n\n
The Benefits of Advanced Encryption Standard (AES)<\/h2>\n\n\n\n
A Brief History of the Advanced Encryption Standard<\/h2>\n\n\n\n
Selection Process of the AES Algorithm<\/h2>\n\n\n\n
What\u2019s the Difference Between DES and AES Encryption Algorithms?<\/h2>\n\n\n\n
<\/strong><\/td> DES Encryption<\/strong><\/strong><\/td> AES Encryption<\/strong><\/strong><\/td><\/tr> Still In Use and Considered Secure?<\/strong><\/td> No \u2014 DES has known vulnerabilities that can be exploited<\/td> Yes \u2014 AES has no known vulnerabilities, currently accepted as the standard for symmetric encryption<\/td><\/tr> Cipher Structure<\/strong><\/td> Based on the Feistel structure<\/td> Based on a substitution-permutation network<\/td><\/tr> Key Sizes<\/strong><\/td> Key size is 64 bits (8 of which are parity bits, meaning it\u2019s really a 56-bit key)<\/td> Keys are available in 128 bits, 192 bits, or 256 bits<\/td><\/tr> Block Sizes<\/strong><\/td> 64-bit block size<\/td> 128-bit block size<\/td><\/tr> Encryption Rounds<\/strong><\/td> 16 rounds of encryption<\/td> Number of rounds depends on the key-length used \u2013 128-bit key has 10 rounds, – 192-bit key has 12 rounds, and – 256-bit key has 14 rounds.<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n How Does AES Encryption Work?<\/h2>\n\n\n\n