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What is Cryptography?

Cryptography is the practice of developing and using techniques that prevent data from being read or tampered with by unauthorized parties.


The primary goal of cryptography is to ensure that the transmitted information can only be read by the intended recipient. Cryptography is used in various fields, including warfare, cybersecurity, finance, communications, and more.

What is Cryptography?

Key Takeaways

  • Cryptography is the process of ensuring that messages can only be interpreted by the intended recipient.
  • Core techniques involve encryption (converting plaintext to ciphertext) and decryption (reverting ciphertext to plaintext) using keys.
  • There are various types of cryptographic techniques, including symmetric encryption, asymmetric encryption, hash algorithms, and digital signatures.
  • Cryptography is the first line of defense in cybersecurity as it secures communications, authenticates users and devices, and protects stored data.
  • Cryptography use cases include secure communications, online transactions, and password protection.

    History of Cryptography

    Cryptography has been used by humans for thousands of years. The oldest known text to contain cryptography is said to have occurred in 1900 BC in Egypt when inscriptions were carved into the wall of a tomb.

    Julius Caesar is known to use simple cryptography techniques such as alphabet substitution in his government communications. This disguised way of writing is called a cipher. Ancient Hebrews also practiced similar cryptography techniques called reversed-alphabet simple substitution cipher.

    Modern cryptography techniques are said to have originated at the outbreak of World War I when cryptography was widely used for military communications. It was during the same time that cryptanalysis – which refers to the process of understanding hidden messages and decoding cryptography – gained prominence as well.

    During World War II, British mathematician Alan Turing made a critical breakthrough for the Allied Forces in devising techniques for decoding German ciphers.

    By 1975, researchers at IBM had developed the Data Encryption Standard (DES) which was used by the US government and was highly influential in advancing modern day data security.

    How Does Cryptography Work?

    How Does Cryptography Work?

    The process of cryptography begins with an unencrypted message known as plaintext, which is encrypted into an unreadable code and then reversed back to its original form by the intended recipient.

    Cryptography relies on encryption and decryption processes to ensure secure passage of data between trusted parties.

    Encryption is the process that converts readable data into an unreadable code known as ciphertext. Various encryption techniques convert messages into random sequences of alphanumeric characters, making it unintelligible to anyone.

    In order to read the encrypted message, the recipient must decrypt the ciphertext.

    Decryption refers to the process of converting ciphertext back into readable text. Only users with the correct decryption key can reverse the encryption process and retrieve the original plaintext.

    Types of Cryptographic Techniques

    There are various types of cryptographic techniques, each with its own strengths and weaknesses. Some of them are:

    Symmetric encryption
    These encryption systems use a common key for both encryption and decryption. 

    Asymmetric encryption
    These encryption systems use two keys instead of a single, common key. The public key is used for encryption, while the private key is used for decryption. Asymmetric encryption is also known as public key encryption.

    Hash algorithms
    Hash algorithms convert a message of any length into a fixed-length output called hash value.
    Digital signatures
    Digital signatures are cryptographic proofs that provide assurance that the claimed signatory signed the information and that the message was not modified after signature generation.

    Cryptography Features

    Key features of cryptography include:


    Cryptography ensures that only authorized parties can access and understand the encrypted data.

    Cryptographic techniques ensure that messages are not altered or tampered with during transmission.

    Cryptography ensures accountability from the sender of the message with the use of digital signatures. The sender cannot deny their actions once they sign and send a message.

    Applications of Cryptography

    Applications of Cryptography

    The main use cases of cryptography are:

    Cryptography is used to obscure stored passwords and validate password authenticity.

    Messaging applications like WhatsApp and iMessage use end-to-end encryption to ensure that messages can only be read or listened to by the sender and intended recipient.

    Secure web browsing
    Data transmitted over the Internet are encrypted using common transport encryption protocols such as Hypertext Transfer Protocol Secure (HTTPS) and Transport Layer Security (TLS). HTTPS is commonly used to secure websites so that personal information and messages are not intercepted by a third party.
    HCryptography encryptions are crucial in ensuring that credit card details, passwords, and other sensitive information are not leaked when making e-commerce payments.
    Cryptocurrencies rely on complex data encryptions to ensure that transactions stored in a blockchain ledger cannot be changed or tampered with.
    Identity authentication
    Digital signatures are used in crypto wallets to authenticate transactions. Digital signatures prove that a user is the true owner of a particular crypto asset.
    Data storage
    Encryption technology is used in smartphones, computers, and cloud devices to protect stored data.

    Why is Cryptography Important in Cybersecurity?

    Cryptography is a critical component of cybersecurity. Today, global interconnectedness has made advancements in cybersecurity and cryptography more important than ever. Without strong cryptography, Internet users will fall prey to identity theft, Internet extortion campaigns, data breaches, and more.

    Cryptography is the first line of defense in cybersecurity as it secures communications between websites and servers, authenticates users and devices, and safeguards data stored on various devices and systems. Without cryptography, sensitive personal information such as financial authentication and intellectual property would be vulnerable to exploitation by cybercriminals.

    Cryptographic Key Attacks and Risks

    Cryptography techniques are not immune to attacks and vulnerabilities.

    Some common cryptographic attacks and risks include:

    Weak keys
    Cryptographic keys tend to be more difficult to crack the longer they are. Inadequate key lengths can turn into a cryptographic vulnerability.

    Brute force attacks
    Brute force attacks are a simple hacking technique that uses trial and error to crack encryption keys.

    Quantum computing
    Quantum computing is an advanced technology that solves complex problems faster than classical computers and supercomputers. Experts theorize that quantum computing can successfully attack encryption methods in days compared to months and years taken by older methods.
    Man-in-the-Middle attacks (MITM)

    How to Minimize the Cryptography Risks

    To mitigate cryptographic risks, you can implement the following best practices:

    • Use strong encryption algorithms.
    • Implement proper key management procedures to securely generate, store, and distribute cryptographic keys.
    • Regularly update cryptographic systems to keep up with the latest standards and technologies to address emerging threats.
    • Monitor cryptographic systems for unusual behavior or signs of unauthorized access.

    Cryptography Pros and Cons

    In this section, we sum up the advantages and disadvantages of cryptography.


    • Protects sensitive and personal information from unauthorized access
    • Ensures that only the intended recipient can interpret the encrypted message
    • Provides proof that messages are not altered or tampered with
    • Guarantees that senders and receivers are accountable for encrypting and decrypting data


    • Implementing cryptography requires technical knowledge of the subject
    • Poor key management can lead to security vulnerabilities and data breaches
    • Encryption methods and protocols continually evolve, with older techniques at risk of obsolescence due to emerging threats like quantum computing.
    • Cryptography is not foolproof. There are various ways to crack encryption

    Bottom Line

    Cryptography is a key aspect of modern cybersecurity. We use cryptography in our everyday lives, whether we are using the Internet, creating a new password or making e-commerce payments. Without cryptography, our sensitive data would be vulnerable to unauthorized access and misuse.


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    Mensholong Lepcha
    Crypto & Blockchain Writer
    Mensholong Lepcha
    Crypto & Blockchain Writer

    Mensholong is an experienced crypto and blockchain journalist, now a full-time writer at Techopedia. He has previously contributed news coverage and in-depth market analysis to, StockTwits, XBO, and other publications. He started his writing career at Reuters in 2017, covering global equity markets. In his free time, Mensholong loves watching football, finding new music, and buying BTC and ETH for his crypto portfolio.