What is Cryptography? Definition, Importance, Types

October 12, 20217:47 pm

Single-key or symmetric-key encryption algorithms create a fixed length of bits known as a block cipher with a secret key that the creator/sender uses to encipher data and the receiver uses to decipher it. One example of symmetric-key cryptography is the Advanced Encryption Standard . AES is a specification established in November 2001 by the National Institute of Standards and Technology as a Federal Information Processing Standard to protect sensitive information. The standard is mandated by the U.S. government and widely used in the private sector. Public key cryptography , or asymmetric cryptography, uses mathematical functions to create codes that are exceptionally difficult to crack.

Cryptography Types

Cryptographic hash functions and message authentication codes enable integrity verification by producing unique fixed-size digests for every input. Cryptography what is cryptography is the heart of security and privacy mechanisms worldwide. It transforms plain-text data into ciphertext in an unreadable format using encryption algorithms.

AES Encryption or Advanced Encryption System

Unlike Triple DES, RSA is considered an asymmetric algorithm due to its use of a pair of keys. You’ve got your public key to encrypt the message and a private key to decrypt it. The result of RSA encryption is a huge batch of mumbo jumbo that takes attackers a lot of time and processing power to break. One or more cryptographic primitives are often used to develop a more complex algorithm, called a cryptographic system, or cryptosystem. Cryptosystems use the properties of the underlying cryptographic primitives to support the system’s security properties.

Cryptography Types

These values create unique hash values of fixed length, ensuring secure handling. They work by turning an input message into a fixed-length hash value — an essential process ensuring data security and integrity. One of the key characteristics of hash functions is their deterministic nature, meaning they always produce identical output given identical input. Furthermore, hash functions are designed to be quick and efficient, with large data sets allowing for quick computation.


Public-key algorithms are based on the computational difficulty of various problems. Much public-key cryptanalysis concerns designing algorithms in P that can solve these problems, or using other technologies, such as quantum computers. Thus, to achieve an equivalent strength of encryption, techniques that depend upon the difficulty of factoring large composite numbers, such as the RSA cryptosystem, require larger keys than elliptic curve techniques.

In 2012, the court ruled that under the All Writs Act, the defendant was required to produce an unencrypted hard drive for the court. Cryptography is central to digital rights management , a group of techniques for technologically controlling use of copyrighted material, being widely implemented and deployed at the behest of some copyright holders. This had a noticeable impact on the cryptography research community since an argument can be made that any cryptanalytic research violated the DMCA. Similar statutes have since been enacted in several countries and regions, including the implementation in the EU Copyright Directive.

Incorrect Use of Keys

The encrypted message will be delivered to the receiver then the receiver will use the secret key to decrypt the message. The message will be secured because of its uniqueness even when the hacker intercepts the message with the public key, they cannot decrypt it with their own decryption since it is only the private key who can decrypt it. There will be no risk for the communication since it is invulnerable and difficult in interception. One of the main weakness of asymmetric key encryption is the speed of encryption. It is slower than symmetric method as both sender and receiver uses different types of keys for it to be secured enough from the hackers to crack the public and secret key. Key management and validation are also makes the asymmetric encryption weak.

  • This means that elliptic curve cryptography uses less storage, processing power, and energy to protect data at the same level as an equivalent integer-based algorithm.
  • Typical key lengths are 128 and 256 bits for private keys and 2048 for public keys.
  • The Greeks of Classical times are said to have known of ciphers (e.g., the scytale transposition cipher claimed to have been used by the Spartan military).
  • Extensive open academic research into cryptography is relatively recent, beginning in the mid-1970s.
  • Asymmetric key cryptography is also called as public key cryptography or conventional cryptographic system.
  • A common example of this is the messaging tool WhatsApp, which encrypts conversations between people to ensure they cannot be hacked or intercepted.

Finally in a man-in-the-middle attack Eve gets in between Alice and Bob , accesses and modifies the traffic and then forwards it to the recipient. Diffie and Hellman’s publication sparked widespread academic efforts in finding a practical public-key encryption system. This race was finally won in 1978 by Ronald Rivest, Adi Shamir, and Len Adleman, whose solution has since become known as the RSA algorithm. As well as being aware of cryptographic history, cryptographic algorithm and system designers must also sensibly consider probable future developments while working on their designs. For instance, continuous improvements in computer processing power have increased the scope of brute-force attacks, so when specifying key lengths, the required key lengths are similarly advancing.

Applications of Cryptography –

The hash function is also considered as a mathematical equation that takes seed and produce the output that is called hash or message digest. In the digital realm, encryption and decryption are at the core of modern cryptography. Encrypting, which converts plain text to cipher text, ensures that only intended https://xcritical.com/ recipients can access information. The major drawback of this symmetric-key encryption is sharing the secret key. Much of the theoretical work in cryptography concerns cryptographic primitives—algorithms with basic cryptographic properties—and their relationship to other cryptographic problems.

Cryptography Types

In both cases, the Motion Picture Association of America sent out numerous DMCA takedown notices, and there was a massive Internet backlash triggered by the perceived impact of such notices on fair use and free speech. Cryptography has long been of interest to intelligence gathering and law enforcement agencies. Because of its facilitation of privacy, and the diminution of privacy attendant on its prohibition, cryptography is also of considerable interest to civil rights supporters. Accordingly, there has been a history of controversial legal issues surrounding cryptography, especially since the advent of inexpensive computers has made widespread access to high-quality cryptography possible. Some widely known cryptosystems include RSA, Schnorr signature, ElGamal encryption, and Pretty Good Privacy . More complex cryptosystems include electronic cash systems, signcryption systems, etc.

Asymmetric Key Systems

Symmetric encryption is an old algorithm, but it is faster and efficient than asymmetric encryption. Because of great performance and fast speed of symmetric as compare to asymmetric encryption. After creating a hash of a file or a password via a hash function, it is impossible to revert/decipher the text, unlike encryption, it does not incorporate the use of keys. A reliable hash function should make it really hard to crack the hashed credentials/files to their former state. Moreover, AES, a successor of the Triple-DES, is an ideal algorithm for a wireless network that incorporates the WPA2 protocol and remote-control applications. AES is the preferred choice for quick encrypted data transfer to a USB, for Windows Encrypting File System , and used for disk encryption techniques.

Cryptographic hash functions

Shanika Wickramasinghe is a software engineer by profession and a graduate in Information Technology. Shanika considers writing the best medium to learn and share her knowledge. She is passionate about everything she does, loves to travel and enjoys nature whenever she takes a break from her busy work schedule. However, there are still several exploitable vulnerabilities in the RSA. For example, researchers were able to crack a key 768-bit RSA algorithm. The 2016 FBI–Apple encryption dispute concerns the ability of courts in the United States to compel manufacturers’ assistance in unlocking cell phones whose contents are cryptographically protected.

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