Difference Between Rijndael and Rijndaelmanaged

January 2022 · 5 minute read

Cryptology bisects into cryptography and cryptanalysis. Further, cryptography assorts into a symmetrical algorithm and asymmetrical algorithm and protocols. Cryptography is the introduction of encryption on the sender side followed by decryption on the receiver side. This prevents access by an opponent. Rijndael and rijndaelmanaged are such algorithm. It was officially accepted in 2000.

Rijndael vs Rijndaelmanaged

The main difference between Rijndael and Rijndaelmanaged is that the former is the base class. The latter is a derived class. A base class is a fundamental class that allows further extraction of classes. A derived class takes after the base class. A programmer can outstretch the capabilities of the derived class.

Rijndael is an encoding algorithm. Two Belgian scholars namely Joan Daemen and Vincent Rijmen introduced the world to an advanced encryption algorithm. In 1997 they initiated the formation of Rijndael. As by the name, we can tell Rijndael is the blend of Daemen and Rijmen. NIST or the National Institute of Standard Technology established Rijndael as AES’s candidate.

Rijndaelmanaged is the extended class of Rijndael. It utterly inherits the code of the base class (here Rijndael) apart from the initialization and destruction. We can not inherit Rijndaelmanaged as it is a sealed class. The purpose to seal Rijndaelmanaged is to prevent it from further extending by the programmers.

Comparison Table Between Rijndael and Rijndaelmanaged

Parameters of comparisonRijndaelRijndaelmanaged
Class Base classDerived class
Property InheritableNon – inheritable
Category Public abstract classPublic Sealed class
Instantiation Automatically instantiated It is not automatically instantiated
Dependency It need not contact the derived classIt may contact the base class while initiating

What is Rijndael?

With the collapse of DES, the US government was in desperate need of an advanced encryption algorithm. NIST initiated an internationally open competition in 1997. Fifteen candidates came up with 15 different types of algorithms. Among them, five of them succeeded in the next round. Rijndael earned the stage in 2000. 

Rijndael was designed efficiently by Vincent Rijmen and Joan Daemen. Rijndael is a block cipher. Block cipher is nothing but the encryption of plain text into ciphertext using a cipher key and vice versa. It is composed of boolean permutations that operate on bit vectors.

The block length and key length vary in Rijndael to any multiple of 32 bits. The minimum is 128 bits and the maximum being 256 bits. The number of rounds is proportional to the key length. 10 rounds for 128 bits, 12 rounds for 192, 14 for 256. The security tightens with an increase in rounds. Each round consists of 4 sequences. SubBytes step followed by the ShiftRows step followed by the MixColumns step and finally the Key Addition step.

While designing Rijndael three criteria were considered, they are as follows

  • Prevention from all the attacks,
  • Design intelligibility
  • Code conciseness and speed on the broad- spectrum.
  • What is Rijndaelmanaged?

    Rijndaelmanaged is the derived class of Rijndael. It inherits the implementation of Rijndael. Like Rijndael, it is also a block cipher. The plain text is processed in blocks. It is a cryptography algorithm. 

    Rijndaelmanaged is private key cryptography. It utilizes one private key to encrypt the plain text into ciphertext and decrypt the ciphertext into plain text. 

    Application of Rijndaelmanaged

    .NET

    .NET core

    .NET framework

    .NET standard

    Xamarin.Android

    Xamarin.iOS

    Xamarin.Mac

    What it implies is that Rijndaelmanaged is a theoretical execution of Rijndael. We can not instantiate it. We can create an implementation of the base class that embodies a particular code and name it accordingly. This is because we can implement from the base class and then exchange the layout of the derived class. The block length and the key length resemble that of the Rijndael.

    A derived class like Rijmdaelmanaged is referred to as non-inheritable in contrast to its base class. Rijndaelmanaged belongs to the ‘public sealed’ category. The seal implies that this class of algorithm cannot be further inherited or extended, unlike the base abstract class. The namespace used for Rijndaelmanaged is similar to that of Rijndael. They fall under the Namespace ‘system.security.cryptography’.

    Main Differences Between Rijndael and Rijndaelmanaged

  • Rijndael is the base class while Rijndaelmanaged is the derived class.
  •  Rijndael can instantiate on its own while the latter is incapable to do so.
  • Rijndael falls under the category of ‘public abstract class’ whereas Rijndaelmanaged falls under ‘public sealed class’.
  • The former is inheritable unlike the latter, which can not be inheritable.
  • The former being the mother of the latter need not depend on it, whereas the Rijndaelmanaged might need to contact the base class during instantiation.
  • Conclusion

    When addressing encryption, the vital component we require is crypto. Crypto is the fundamental ingredient to be precise. Through ages of practice, we have landed on the most advanced algorithm stage. By the end of 1997, DES went through severe threats, and its security became suspicious. NIST called for AES or Advanced Encryption Standard. National Institute of Standards and Technology concocted an open competition where people from all over the continents can exhibit their algorithms. During this event, two Belgian men were successful to seal the opportunity with their unique and effective algorithm.  

    Rijndael is thus an encoding algorithm that promotes advanced security. Rijndaelmanaged on the other hand is the derivative of Rijndael. It inherits all the framework of Rijndael and differs in the constructors and the destructors. Rijndael is one of the widely used algorithms. NASA (National Aeronautics and Space Authority), NSA (National Security Agency) are among the notable groups that use Rijndael. Rijndael is classified as a block cipher that encodes blocks of 128 bits, 198 bits, 256 bits. It utilizes symmetric keys accordingly. The rounds vary with the corresponding key length used. 

    Rijndaelmanaged has the same layout except it falls under the ‘public sealed class’ unlike its base abstract class, Rijndael. Rijndael is considered inheritable but Rijndael is considered non-inheritable. Rijndaelmanaged has the implementation of Rijndael.

    References

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