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What Is Cryptography? A Beginner’s Guide
Introduction
Network security is more important than ever because the world has become a global village. Cryptography is the study of hiding the meaning of data so that only certain people can figure out what it means. In simple terms, you can think of it as writing in secret. It’s been around a long because the government used cryptography and coded transmissions to hide their messages from the enemy. Cryptography and network security are more important than ever because of the growth of the internet. This is especially true when it comes to protecting banking information, personal information, and private information.
In this article, we will study Cryptography and learn about blockchain cryptography, and the terms used in cryptography. We will also find out what the future of cryptography will be and how this is changing how we use the internet.
What Is Cryptography in Blockchain?
Cryptography is the mechanism for preventing unwanted access to sensitive data. Cryptographic methods are included in the blockchain’s security standards. It ensures the security of a transaction between two nodes in a blockchain network. The three basic foundations of blockchain technology are the distributed ledger, peer-to-peer network, and cryptographic security.
Without a comprehensive security method, it is difficult for a distributed ledger system and a point-to-point network to operate successfully and securely. Blockchain, namely Cryptography and Hashing, use two sorts of security methods. The primary distinction between these two is that P2P (Peer-to-Peer) networks employ cryptography to encrypt communications. Hashing is used to safeguard block data and connect blocks in a blockchain. Crypto, which means “hidden,” and Graphy, which means “writing.” Cryptography is thus a way of transforming plaintext into unreadable coded text.
Encryption and Decryption are two key ideas underlying cryptography; encryption is the process of encoding data so that you and I cannot decipher its meaning just by looking at it, whereas, decryption is the opposite of encryption or the decoding of encoded data.
History of Cryptography
Let’s take a brief look at the history of cryptography before moving on to more advanced topics. The history of cryptography thousands of years ago. In ancient Egypt, one of the oldest indications of using cryptographic systems to communicate vital information was discovered. During this period, Roman generals used a famous cryptographic method known as the “Caesar cipher.”
The period of encryption techniques in cryptography began in the sixteenth century. This type of key encryption encodes a message using a single keyword. The recipient then uses the key to decode the communication. This technique was often known as the “Vigenere cipher.”
Later in the 20th century, rotor-driven encryption devices emerged, such as the German Enigma system used during World War II. These devices would create cipher text by configuring the many rotors to certain parameters.
This form of cryptography was believed to be successful and unbreakable for a considerable time. In 1932, however, Polish and British soldiers (with the assistance of the renowned Alan Turing) discovered the flaw in this system and could decipher Enigma-encrypted signals.
With the end of the war era, the computer age emerged, and with it, the need for more powerful cryptographic algorithms. During this period, it became apparent that cryptography may be used in other critical fields, such as business and trade, in addition to warfare.
IBM developed a cryptographic technique known as “Data Encryption Standards” (DES) in the 1970s to encrypt sensitive data. It was simple to hack or brute-force this technique. Therefore, it quickly became outdated. In 2000, the Advanced Encryption Standard followed DES (AES).
In addition to its everyday application in emails, communications, Login IDs and passwords, etc., cryptography is very important in functioning cryptocurrency systems like Bitcoin. Cryptographic methods are mostly used for hashing, key encryption, and digital signatures to protect the data.
Terminologies Used in Cryptography
Plain Text
Plaintext refers to unstructured text that has not been coded, formatted, or modified for computer processing.
Encryption
Encryption encrypts data or a message so that only the person on the other end can decode it. Encryption does not guarantee interference-free communication but makes the information unintelligible to any would-be snoopers.
Cipher Text
Cipher text-It is the encrypted text. The plaintext is what you have before encryption, while cipher text is the encrypted output. The word cipher is occasionally used as a synonym for cipher text; however, it more properly means the technique of encryption rather than the outcome.
Decryption
Decryption-Decryption is taking encoded or encrypted text or other material and transforming it into text that you or the computer can read and understand.
Key
A key is a string of letters used inside an encryption technique to transform data so that it seems random. It locks (encrypts) data similarly to a physical key so that only someone with the correct key may unlock (decrypt) it.
AES Encryption
The AES Encryption algorithm (also known as the Rijndael algorithm) is a 128-bit symmetric block cipher method. It translates these individual blocks using 128-, 192-, and 256-bit keys. It encrypts these blocks and then connects them to generate the ciphertext.
It is built on a substitution-permutation network or SP network. It comprises a sequence of connected processes, such as substituting inputs for particular outputs (substitutions) and others requiring bit shuffling (permutations).
DES Encryption
The Data Encryption Standard (DES) is a block cipher technique in cryptography that transforms plain text in 64-bit blocks to ciphertext using 48-bit keys. It is a symmetric key algorithm that uses the same key to encrypt and decrypt data.
RSA Encryption
The RSA algorithm is a kind of asymmetric cryptography algorithm. Asymmetric indicates that it operates on two distinct keys: the Public Key and the Private Key. As the name implies, the Public Key is distributed to everyone while the Secret Key is kept private. RSA keys are normally 1024 or 048 bits long; experts anticipate that 1024-bit keys will be cracked shortly. But, as of today, it seems to be an impossible task.
AES 256 Encryption
AES-256, which has a key length of 256 bits, offers the biggest bit size and is practically unbreakable by an attacker with today’s computational power, making it the most secure encryption standard. AES 256 uses symmetric key encryption. This indicates that the same secret key is used for encryption and Decryption and that both the sender and recipient of the data must possess a copy of the key.
Symmetric Cryptography
Symmetric encryption, also known as symmetric-key cryptography, encrypts and decrypts data using a single key. This key must be shared with the receiver. Assume you wish to say, “I love you, Mom.” You would type your email, then encrypt it using a secret key. When Mom gets the email, she will input the secret key to decrypt it.
Asymmetric Cryptography
Asymmetric encryption is a kind of encryption that encrypts and decrypts data using two distinct but mathematically linked keys. The public key encrypts data, whereas the private key decrypts it. Because of this, it is also referred to as public-key encryption, public-key cryptography, and asymmetric-key encryption.
Public Key Cryptography
Public-key cryptography, also known as asymmetric cryptography, is an encryption system that employs two keys that are mathematically related but not identical – a public key and a private key. Unlike symmetric key techniques, which use the same key to encrypt and decode, each key has a distinct purpose. Encryption is performed using the public key, while Decryption is performed using the private key.
Elliptic Curve Cryptography
ECC is a strong cryptography method. It creates security between key pairs for public-key encryption using elliptic curve mathematics. ECC has progressively been gaining popularity lately because of its lower-key size and ability to maintain security. This trend will likely continue as the requirement for devices to stay safe grows due to the increasing size of keys, which draws on restricted mobile resources.
Public Key Encryption
A pair of mathematically related keys are used in public-key encryption. A communication encrypted with the first key must be decrypted using the second key, and a message encrypted with the second key must be decrypted using the first.
A pair of keys are issued to each participant in a public key system. One key is designated as the private key and is kept confidential. The other key, known as the public key, is released to anybody who requests it.
Anyone may use your public key to encrypt a message, but only you can read it. When you get the communication, you use your private key to decode it.
How Does Cryptography Work?
As seen in the figure, this is the fundamental operation of cryptography. Two parties are identified as the sender and receiver. The first message is known as the Plaintext. This Plaintext is sent to the encryption server by the sender, where the encryption method is used with the secret key to produce Ciphertext as the encrypted output.
This Ciphertext is the encrypted output that enters the decryption server from the public domain, where the decryption technique is done with the secret key and the plaintext or original message is returned as output.
Blockchain Symmetric Cryptography
The first key cryptography approach used in a blockchain network was symmetric cryptography. In this strategy, both nodes encode and decode using the same key (or encrypt and decrypt).
Assume Node A wishes to relay secret information to Node B. Node A will encrypt the information into unreadable ciphertext using key k1 and deliver it to Node B to support this transfer using the symmetric key approach. Node B receives the ciphertext and decrypts it with the same key, k1. This implies that both Node A and Node B must have the same key, k1. Similarly, if Node A wishes to interact with Node C, they need a new key k2 between them. Alternatively, Node B and Node C will need a new key k3 to complete a transaction.
As a result, although being the quickest way, one significant disadvantage of this technique is that a node will require many keys to communicate with other nodes in the network. Furthermore, the nodes must ensure that they securely exchange the key, or a third node may get it. Because of these limitations, another type of asymmetric key cryptography emerged.
Blockchain Asymmetric Cryptography
Asymmetric cryptography, as the name implies, does not require two nodes sharing the same key. In this sort of key encryption, a node has two keys: a private key and a public key. These keys are usually found in pairs since they function in tandem. We encrypt the message using the public key and decode it with the associated private key.
Consider a network with three nodes: A, B, and C. Each node will have a unique set of private and public keys. The public key is made public, which means that every other node in the network is aware of it. On the other hand, a private key must not be exposed to others and must be kept secret by the node, much like a password.
Let’s look at an example of a transaction between two nodes utilizing a pair of keys. Assume Node A has to transfer secret information to Node B, such as bank account information. Now, Node A will encrypt the content first with its private key and then again using B’s public key. When this encrypted content reaches Node B, it will first decode it with its private key, then use A’s public key.
We need to understand here that the first layer of encryption is when Node A encrypts the message with its private key. It is up to Node B to confirm that the message is coming from Node A.
The next stage of encryption protects the message’s security by coding it with Node B’s public key and decoding it with Node B’s private key. This protects the information from harmful third-party attacks. In asymmetric key cryptography, this is how the two key system works. This is often referred to as Public Key Cryptography.
Hash Function
Hashing is a cryptographic method for converting any kind of data into a unique text string. There is a predictable outcome for each given input. Simply put, putting plaintext through a hashing algorithm yields the same result. Assume you modify anything about the hashing algorithm’s input or plaintext. The hashing result varies as well.
A hash function is an algorithm that converts arbitrary-sized input into a fixed-size output. The result is a ciphered text known as a hash value or a digest. The primary goal of a cryptographic hash function is to validate data.
Passwords often employ hash functions. They are kept in safe databases as hash values or digests and should never be stored in plain text in any database. When you log in, your password is hashed into a digest and compared to one in a database. Remember that a hash algorithm or function is primarily used for comparison, not encryption.
A hash function has the following properties
Deterministic
For every given result, the output will be the same. We can’t reverse a hash algorithm to return to the original password.
Collision resistance
It means that two inputs do not produce the same output.
Non-predictable
A hash function creates an unpredictably unique hash result at random.
Compression
The hash function’s output is substantially smaller than the input size.
Dependable
A hash function cannot be reversed. It only works in one direction.
Unique
No two datasets can generate the same digest. The hash function produces fixed-size digests.
Why Should You Use a Hash Function in Cryptography?
The following are the reasons justifying the use of the hash function in cryptography.
Guarantee Data Integrity
In public-key cryptography, hash functions guarantee the integrity of data. Hash functions act as checksums or techniques to determine whether signed data has been altered. It also functions as an identity verification mechanism.
Protect Against Unauthorized Alterations
One of the finest features of a cryptographic hash function is that it ensures data integrity. Does the application of a hash to data imply that the message cannot be altered? No. However, it does alert the receiver that the message has been modified. This is because even the smallest modifications to a message generate a whole new hash value.
Permit You to Validate and Store the Passwords Safely
Numerous websites enable you to save your passwords, so you don’t have to remember them each time you log in. However, keeping such passwords in plaintext on a server accessible to the public is risky since it exposes the data to thieves. Therefore, websites generally hash passwords to create hash values, which they instead keep.
Operate at Diverse Speeds for Diverse Objectives
It is also essential to recognize that hash functions are not universally applicable tools. As previously stated, several hash functions serve distinct purposes based on their design and hash rates. They operate at varied rates, with some being much quicker than others. These speeds may increase or decrease security depending on how you use a hashing method. Others, however, do not fit within the umbrella of secure hashing methods.
Public Key Infrastructure and Cryptography (PKI)
Most people who use the internet are worried about keeping their data and privacy safe. Encryption is a basic security measure that keeps data from being accessed by people who shouldn’t be able to. And public key infrastructure (PKI) is probably the most popular way to use cryptography.
PKI is made up of a set of physical parts (computers and cryptographic software or hardware, like Hardware Security Module “HSM” or smart cards), human processes (checks, validation), and software (system and application), which all work together to issue and manage the life cycle of digital certificates or electronic certificates. These tools make it possible to do cryptographic operations like encryption and digital signatures, which make data transmission more secure in the following ways:
Confidentiality
only the person who has the right to receive (or own) the data can read it;
Authentication
It is for ensuring that a person, system, or other entity is allowed to use system resources (systems, networks, applications, etc.).
Integrity
Integrity means that the data has not been changed by accident or purpose.
Non-Repudiation
It means that the source of the data can’t say that it’s not real.
The Parts of Public Key Infrastructure (PKI)
A certification authority, a registration authority, and a central directory are the main parts of the PKI. These parts work together to distribute and check certificates.
Certification Authority (CA)
Certificates are given to users, computers, and services, and certificates are managed. With its digital certificate, a certification authority signs each certificate it gives out.
Registration Authority (RA)
The point where the user and the certification authority talk to each other. Its job is to find applicants or certificate holders and ensure that the rules about how the certificate can be used are followed.
CD, or Central Directory
Keeping digital certificates safe is their job. It makes it easier to organize and store certificates. It also keeps track of the list of certificates that have expired or been taken away (CRL) and gives all users access to public-key certificates issued by the certification authority.
Cryptography is a way to protect data by turning it into a format that can’t be read. This can be done to send or store the data. Cryptography is an important technology for online shopping, intranets, extranets, and many other web applications.
PKI Is Used in the Following Ways
A list of certificates from different Certification Authorities is built into web browsers. These certificates are chosen by the developers of the browser based on their own rules. When a person or company wants to set up a web server that uses HTTPS and the Transport Layer Security protocol (TLS), it makes a public and private key.
Then, it sends a certificate signing request (CSR) with its public key and information about who it is to one of the Certification Authorities. After a registration authority (RA) verifies the applicant’s identity, the Certification Authority signs the CSR with its private key (not the person’s private key), makes a certificate, and sends it back to the person who asked for it.
The returned certificate is added to the web server of the applicant. When a user connects to this web server, it sends the certificate that the Certification Authority has already given. The client’s web browser verifies the server’s certificate by using the signed certificate of the Certificate Authority. So, the Certification Authority lets the user know the server is who it says it is. The web browser contacts the relevant Certification Authority to see if the server’s certificate has been revoked.
Private Key Encryption in Cryptography
Private key encryption is a type of encryption where information can only be encrypted and decrypted with a single private key. Since only one key is used, it goes quickly. But when everyone uses private keys, protecting one key makes it hard to keep track of all the keys. The private key could be lost or given away. Key management avoids these risks, often changing the encryption key and giving the key to the right people.
Simple to Use
One of the benefits of private key encryption is its simplicity. The procedure is virtually transparent since the system must complete a single, reversible mathematical calculation to encrypt or decode a file. Encrypting whole file systems protects them from prying eyes. File access is rapid and uncomplicated as long as everyone has been confirmed as the cryptographic key is saved on the system.
Potential for Exposure
The primary drawback of a private key encryption method is that anybody new must have access to the key. This access may need sending the key over an unsafe form of communication. For example, if you wish to communicate by email using a private key encryption scheme, you must first provide the key to your correspondent. A third party may intercept data during transmission and get access to the key that unlocks your encrypted connection.
Effort Required
Maintaining strong security procedures using a private key system might be difficult. The most basic encryption approach employs a single key for everything, but anybody with that key can decode all your encrypted data. You must produce and maintain numerous private keys if you wish to separate groups. You may also need to encrypt the same material many times to give it to various parties. Furthermore, utilizing a single private key for everything exposes you to the risk of an outside attack since everyone with whom you share the key is a possible target for malware infection or hacker attack. If an outsider compromises someone in a multiple-key configuration, they can only access the files and papers that the person has access to, rather than the whole system.
Digital Signature in Cryptography
Digital signatures are the first step in authenticating a message using a public key. In the real world, signing handwritten or typed messages with your own handwriting is common. They are used to make the signer responsible for the message.
In the same way, a digital signature is a way to link a person or thing to digital data. This binding can be checked by both the receiver and any other third party.
The signer is the only one who knows the secret key used to calculate the digital signature.
In the real world, the person who gets a message needs to know that it came from the person who sent it, and he shouldn’t be able to deny that. This is a very important requirement for business applications, where there is a high chance of a disagreement over the data being exchanged.
Why Is a Digital Signature Important?
The digital signature that uses public-key cryptography is the most important and useful tool for securing information out of all the cryptographic primitives.
In addition to ensuring that a message can’t be changed, a digital signature verifies the message and ensures that the data is correct. Let’s take a quick look at how the digital signature does this.
Message authentication
When the verifier checks a sender’s digital signature with the sender’s public key, he knows that only the sender, who has the secret private key, could have made the signature.
Data Integrity
If an attacker gets access to the data and changes it, verifying the digital signature at the receiver end fails. The output of the verification algorithm and the hash of data that has been changed will not match. So, the message can be safely denied by the receiver if they think that data integrity has been broken.
Non-Repudiation
Since it is assumed that only the signer knows the signature key, he can only sign a piece of data once. So, if a dispute arises in the future, the person who gets the message can show the data and the digital signature to a third party as proof.
By adding public-key encryption to a digital signature scheme, we can make a cryptosystem that has the four most important security features: privacy, authentication, integrity, and the ability to prove that something is what it says it is.
Quantum Cryptography
Cryptography is the technique of encrypting data or transforming plain text into scrambled language so that only those with the correct “key” can decipher it. Quantum cryptography just employs the laws of quantum physics to encrypt and transfer data unbreakably.
Quantum cryptography, also called quantum key distribution (QKD), sends information from one place to another using a series of photons and tiny particles of light. By measuring the properties of a small number of these photons and comparing them, the two ends can figure out the key and if it is safe to use.
The process is easier to understand when it is broken down further.
- The sender sends photons through a filter (or polarizer), which randomly gives them one of four polarizations and bit numbers: vertical (one bit), horizontal (zero bit), 45 degrees to the right (one bit), or 45 degrees to the left (zero bit) (Zero bit).
- The photons go to a receiver, which uses two beam splitters (horizontal/vertical and diagonal) to “read” the polarization of each photon. The receiver can’t tell which beam splitter to use for each photon, so it has to guess.
- Once the stream of photons has been sent, the receiver tells the sender which beam splitter was used for each photon in the order it was sent. The sender then compares this information with the order of polarizers used to send the key. The photons read with the wrong beam splitter are thrown away, and the sequence of bits left over is used as the key.
If a snoop reads or copies the photon in any way, the state of the photon will change. The endpoints will pick up on the change. This means that you can’t read the photon, send it to someone else, or make a copy of it without being caught.
Cryptography Pros and Cons
Modern cryptography offers sophisticated procedures to guarantee that the adversary’s malicious intents are foiled while legitimate users have access to information.
Pros of Cryptography
- Cryptography is a critical instrument for information security. It offers the four most fundamental information security services.
- Confidentiality An encryption approach may protect information and communication against unwanted disclosure and access.
- Authentication Cryptographic methods like MAC and digital signatures may safeguard data against spoofing and forgery.
- Data Integrity Cryptographic hash functions are important in guaranteeing consumers of data integrity.
- Non-repudiation The digital signature offers a non-repudiation service to defend against disputes that may occur due to the sender’s refusal to forward communication.
- The core services provided by cryptography have made it possible to conduct business through networks utilizing computer systems in an exceedingly efficient and effective way.
Cons of Cryptography
- Aside from the four core principles of information security, a number of additional challenges impact the efficient use of information.
- Even a genuine user may find it difficult to obtain heavily encrypted, authenticated, and digitally signed information at a critical decision-making moment. An intruder may assault the network or computer system and make it inoperable.
- The use of cryptography cannot assure high availability, which is a basic feature of information security. Other approaches are required to protect against threats such as denial of service or full system failure.
- Another essential need for information security, selective access control, cannot be met using cryptography. Administrative controls and procedures must be implemented for the same.
- Cryptography does not protect against the vulnerabilities and dangers that result from the bad system, protocol, and process design. These must be addressed by correct design and the establishment of a protective infrastructure.
- Cryptography is not free. The price is in terms of both time and money.
- The incorporation of cryptographic methods into information processing causes a delay.
- The use of public-key cryptography necessitates establishing and maintaining public key infrastructure, which necessitates a large financial investment.
- The computational complexity of mathematical problems is used to determine the security of cryptography techniques. Any advance addressing such mathematical problems or increased computer power might expose a cryptography system.
Future of Cryptography
It is thus not surprising that demand for cryptographic processing is increasing, with firms using bigger keys, numerous concurrent algorithms, and massive amounts of data every year.
What Role Will Cryptography Play in the Future?
You may use cryptography to ensure that individuals are held responsible and that their activities are correctly documented. With its utilization, electronic commerce may be secured against fraud. The technique may also be used to verify financial transactions. As trade and communications migrate to digital networks, cryptography will become more important in the future.
We look at how we make money from an ATM, watch TV, utilize free software to store emails and files, use our GSM phones, and use our emails in daily settings where cryptography helps a safe service.
Quantum computing will change cryptography, speed up machine learning, and cut the time it takes to solve model optimization problems by a huge amount. It will be interesting to see how companies switch to quantum computing. Cryptography’s future will also ride on this trend, which has the potential to change and disrupts things. We are about to see a huge wave of evolutionary innovations in the next five to ten years. Please tell me what you think about this.
Conclusion
From email to mobile phone conversations, and secure Web access to digital currency, cryptography is an integral component of modern information systems. Cryptography facilitates accountability, justice, precision, and privacy. It is capable of preventing fraud in electronic commerce and validating financial transactions.
Cryptography might safeguard your anonymity or establish your identity. It may prevent vandals from tampering with your website and prevent industrial rivals from accessing your private files. As trade and communications continue to migrate to computer networks in the future, cryptography will become more important.
References
What Is AES Encryption and How Does It Work?
