What is Cryptography?


Cryptography is a technique for encrypting communications and information so that only the target demographic can read and comprehend it.

In computer science, the term “cryptography” refers to safe information and communication methods that use mathematical principles and a system of computations based on rules, or “algorithms,” to change messages in ways that are challenging to read. These employ consistent algorithms in creating cryptographic keys, digital signatures, online browsing on the Internet, and private communications like email and transactions with credit cards.

In this article, we will discuss the following:

  • What is Cryptography?
  • History of Cryptography
  • Cryptography Techniques
  • Cryptographic Algorithm
  • What are Cryptographic Principles?
  • Difference between Symmetric and Asymmetric Cryptography
  • What Problems Does Cryptography Solve?

What is Cryptography?

The field of cryptography consists of highly secured techniques like encryption that only the message’s source and intended target can access. The word comes from the Greek word kryptos, which means to conceal. It has a lot in common with cryptography, transforming simple text into an encrypted message before transmission and back again after the reception. Cryptography also includes techniques like blending and micro dotting to mask information in images. The ancient Egyptians employed these techniques in their intricate hieroglyphs, and Julius Caesar, the Roman Emperor, is credited with creating one of the earliest modern ciphers.

The most typical use of cryptography is to protect and decrypt email and other straightforward messages while sending computer information. The symmetric or “secret key” mechanism is the most straightforward approach. Here, it secures data using a cryptographic key before being transferred to the target for decryption and the encoded message. The issue? A third party has all the tools necessary to decrypt and access the news. Cryptologists created the uneven or “public key” approach to solve this problem. Every user in this scenario has two keys: a public key and a private key.

They encode the message by the sender, who then requests the recipient’s public key before sending it. Only the recipient’s private key will be required when sending the message. Only the recipient’s sensitive information can decode the message after it is delivered, making theft useless without the associated private key.

History of Cryptography

Greek Kryptos, which means buried, is where the name “cryptography” originates. “Writing” is denoted by the suffix “-graphy,” which follows the word “crypt-,” which means “hidden” or “vault. Most historians place the invention of cryptography around 2000 B.C., with the Egyptian usage of hieroglyphics. However, a select group only fully understood intricate pictograms, the meanings of which.

Julius Caesar (who ruled from 100 to 44 B.C.) used the term modern cipher for the first time because he didn’t trust his messengers when he spoke with his governors and commanders. So he devised a mechanism whereby each symbol substitutes his communications with a character three positions higher in the Roman alphabet.

Some of the world’s brightest mathematicians and computer scientists are currently engaged in a war over cryptography. Success in business and combat depend heavily on one’s capacity to safely transfer and preserve sensitive information.

A variety of restrictions in many countries has restricted cryptography. First, however, the amount from limits imposed on the utilization and export of software to improve the accessibility of scientific equations. They used to develop cryptosystems because government agencies do not want specific entities in and out of their regions of the world to have direct connections to ways to receive and transfer confidential messages that may be a danger to national preferences. However, the Internet has made it possible to disseminate powerful software and, more crucially, the fundamental principles of cryptography, such that many of the most cutting-edge cryptosystems and concepts are now available to the general public.

Cryptography Techniques

The fields of cryptology and cryptographic algorithms are closely related to that cryptography. It comprises methods for concealing data while it is being stored or transported, including microdots, word-image fusion, and other techniques. But in today’s computer-centered society, cryptography is most frequently linked with changing plaintext (regular text, also known as cleartext) into ciphertext and back again. Those who work in this area are cryptographers.

  • Privacy: Anyone for whom the information was not of the right thing cannot understand it.
  • Integrity: The content cannot be changed while being stored or transported between the sender and the intended recipient without coming in any notice.
  • Non-repudiation: The person who created or sent the material cannot afterward deny that they had any motivation for doing so.
  • Authentication; Both the sender and the recipient can verify each other’s identities and the information’s source and destination.

Cryptosystems are techniques and protocols that satisfy any or all of the abovementioned requirements. However, they also include the control of human behavior, such as selecting difficult-to-guess passwords, logging off unopened systems, and refraining from addressing sensitive practices with outsiders. Cryptosystems only refer to mathematical procedures and computer programs.

Cryptographic Algorithm

Cryptosystems encode information using cryptographic algorithms, or ciphers, to secure communications between personal computers, devices, and applications.

A cipher suite employs three different algorithms: one for encryption, one for message integrity, and one for encrypting and decrypting. We do this procedure by using protocols that are built into the software and executed by networks of computers and software products (OSes), 

What are Cryptographic Principles?

The most important rule is that you shouldn’t try to create your cryptosystem—the world’s top cryptographers, such as Ron Rivest and Phil Zimmerman. Frequently design cryptosystems with significant security holes. A cryptosystem must pass rigorous testing before being certified “secure” by the security community. Never put your trust in security through obscurity or the possibility that an adversary is unaware of your system. Remember that malevolent insiders and aggressive attackers will target your approach.

When it relates to a safe cryptosystem and financial analysis, the keys are the only elements that should be kept “hidden.” Take the necessary precautions to safeguard any passwords that your machines employ. Never keep encryption keys along with the statistics they’re protecting in plain text. Putting the key beneath the doormat after locking your front door is analogous. A potential attacker will look there first.

  • Keys should be kept in a filesystem and secured with powerful access control lists (ACLs). Keep in mind to follow the least privilege principle.
  • Use a second encryption key to encrypt your document keys (DEKs) (KEK). Creating the KEK using encryption key encryption (PBE) is recommended. An algorithm like bcrypt, scrypt, or PBKDF2 can produce a key using a password, as a small number of administrators can then use this key to reboot the cryptosystem. So this eliminates the requirement ever to save the key elsewhere unencrypted.
  • A tamper-proof hardware appliance includes a dedicated hardware module (HSM) to safely store keys Code can call an HSM’s API to request keys or decrypt data when necessary.

Difference between Symmetric and Asymmetric Cryptography

They use the same key in symmetric cryptography for both encryption/decryption. A wallet share accessible to both the sender and the receiver must already exist. The challenge of key distribution catalyzed the development of asymmetric cryptography.

Asymmetric cryptography encrypts and decrypts data using two distinct keys. Each user has a private and public key in an asymmetric cryptosystem. We can freely share the access policy, but the private key must remain a secret. It can use only the appropriate private key to decrypt data encrypted with a public key. Therefore, sending a message to John must first be encrypted using his public key. Since only John has access to his private key, only John can decrypt the communication. They can only use an associate public key to solve any material they encrypt using a private key. Similarly, Jane might use her private key to sign a message digitally, and anyone possessing Jane’s decryption key could decrypt the copy of the message and confirm that Jane was the one who sent it.

In general, symmetric encryption is quick and works well for encrypting vast volumes of data (e.g., an entire disc partition or database). However, asymmetric encryption is noticeably slower and can only encrypt data in chunks fewer than the key lengths. As a result, symmetric encryption keys are encrypted using asymmetric crypto before being used to encrypt significantly bigger data blocks. In addition, they use Asymmetric crypto to encrypt message hashes rather than the complete message for electronic certificates. Managing cryptographic keys, including their formation, exchange, storage, usage, revocation, and restoration, is done through a cryptosystem.

What Problems Does Cryptography Solve?

Data confidentiality, integrity, availability, authenticity, and non-repudiation should all be assured by a secure system. When appropriately used, crypto assists in offering these guarantees. For example, data at rest and in transit can both have their confidentiality and integrity guaranteed by cryptography. Additionally, it can prevent repudiation and validate senders and beneficiaries to one another.

Several endpoints, often multiple customers, and one or more back-end servers are standard features of software systems. These client-server exchanges happen over unreliable networks. Communication takes place over private networks that could be hacked by outside adversaries or nefarious insiders or over the public, public networks like the Internet. Communications that travel via unreliable networks can be protected. An adversary may try to attack a network using one of two basic types of attacks.

Passive aggression entails the attacker merely hearing on a particular network and trying to read confidential data as it is transmitted. Passive attacks can be offline or online, where the attacker collects traffic in real-time for later viewing—possibly after spending a few months decompiling it. Online passive attacks involve reading traffic in real-time. Active assaults entail the perpetrator pretending to be a client or server, collecting messages in flight, and examining and altering the components before transmitting them to their target.

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