Cryptography 2024: The Ultimate Master Guide to Modern Encryption

These deterministic calculations are employed for cryptographic key generation, advanced digital signing, and verification to ensure information privacy in web browsing and secure communications, such as credit card transactions and email exchanges.

Cryptography techniques & procedures

Cryptography is closely linked to the fields of cryptology and cryptanalysis. It includes techniques such as microdots, combining words with images, and other methods to conceal data during storage or transmission. In today’s computer-driven world, cryptography is most commonly associated with converting plaintext (ordinary text, sometimes referred to as cleartext) into ciphertext (a process known as encryption) and then reversing the process (known as decryption). Experts in this field are called cryptographers.

Current cryptography worries about the accompanying four goals:

Confidentiality: The data cannot be understood by anyone for whom it was unintended.

Integrity: The data cannot be altered in storage or transit between the sender and intended receiver without the modification being detected.

Non-repudiation: The creator or source of the data cannot deny their intent in the creation or transmission of the data at a later stage.

Authentication: The sender and receiver can verify each other’s identities and the origin or destination of the data.

Systems and protocols that meet some or all of the above criteria are known as cryptosystems. While cryptosystems are often thought to refer only to mathematical methods and computer programs, they also encompass the regulation of human behavior, such as choosing difficult-to-guess passwords, logging off unused systems, and not discussing sensitive topics with outsiders.

Cryptography is the process of encoding and decoding information.

Cryptographic Algorithms

Cryptosystems employ a set of techniques known as cryptographic algorithms, or ciphers, to encrypt and decrypt messages, ensuring secure communications between computer systems, devices, and applications.

A cipher suite comprises one algorithm for encryption, another for message authentication, and a third for key exchange. This process, embedded in protocols and coded in software that runs on operating systems (OSes) and networked computer systems, includes the following steps:

• Public and private key generation for data encryption and decryption.
• Digital signing and verification for message authentication.
• Key exchange.

Types of cryptography

Single key or symmetric key encryption algorithms create fixed-length blocks known as block ciphers, using a secret key that the sender/maker uses to encrypt data (encryption) and the receiver uses to decrypt it. One example of symmetric key cryptography is the Advanced Encryption Standard (AES).

AES is a specification established in November 2001 by the National Institute of Standards and Technology (NIST) as the Federal Information Processing Standard (FIPS 197) to protect sensitive data. This standard is mandated by the U.S. government and widely used in the private sector.

In June 2003, AES was approved by the U.S. government for classified information. It is a royalty-free specification implemented in software and hardware worldwide. AES replaced the Data Encryption Standard (DES) and Triple DES (3DES), using longer key lengths—128-bit, 192-bit, and 256-bit—to defend against brute-force and other attacks.

Symmetric cryptography uses a single key, while asymmetric cryptography employs a key pair to encrypt and decrypt data.

Public key or asymmetric key encryption algorithms utilize a pair of keys: a public key associated with the creator/source for encrypting messages and a private key, known only to the originator (unless disclosed or shared), for decrypting that information.

Examples of public key cryptography include:

• RSA (Rivest Shamir Adleman), widely used on the internet.
• Elliptic Curve Digital Signature Algorithm (ECDSA), used by Bitcoin.
• Digital Signature Algorithm (DSA), adopted as the standard for digital signatures by NIST in FIPS 186-4.
• Diffie-Hellman key exchange.

To maintain data integrity in cryptography, hash functions, which produce a deterministic output from an input value, are used to map data to a fixed size. Types of cryptographic hash functions include SHA-1 (Secure Hash Algorithm 1), SHA-2, and SHA-3.

Cryptography concerns

Attackers can bypass cryptography by hacking into computers responsible for data encryption and decryption or by exploiting weak implementations, such as the use of default keys. While cryptography makes it more challenging for attackers to access messages and data protected by encryption algorithms, it is not entirely foolproof.

Growing concerns about the potential of quantum computing to break current cryptographic encryption standards led NIST to issue a call for papers from the mathematics and science communities in 2016 for new public key cryptography standards. NIST has announced that three quantum-safe cryptographic algorithms will be ready for use by 2024.

Unlike today’s computer systems, quantum computing uses quantum bits (qubits) that can represent both 0s and 1s simultaneously, allowing for two calculations at once. While large-scale quantum computers might not be built in the next decade, the current infrastructure necessitates the standardization of publicly known and recognized algorithms that provide a robust approach, according to NIST.

History of cryptography

The word “cryptography” is derived from the Greek word kryptos, meaning hidden.

The word “cryptography” is derived from the Greek prefix kryptos, meaning “hidden” or “vault,” and the suffix -graphy, meaning “writing.”

1. The origins of cryptography are often traced back to around 2000 B.C. with the Egyptian use of hieroglyphics. These complex pictograms had meanings that were understood only by a select few.
2. The earliest known use of a sophisticated cipher was by Julius Caesar (100 B.C. to 44 B.C.), who, distrusting his couriers, developed a system where each letter in his messages was replaced by the letter three positions ahead of it in the Roman alphabet.
3. Recently, cryptography has become a field of expertise for some of the world’s leading mathematicians and computer scientists. The ability to securely store and transmit sensitive information has proven crucial for success in both military and business contexts.
4. Due to national security concerns, governments have imposed various restrictions on cryptography. These limitations range from regulating the use and export of cryptographic software to restricting the public dissemination of mathematical concepts that could be used to develop cryptosystems.

The web has facilitated the distribution of powerful software and, more critically, the underlying principles of cryptography. As a result, many of the most advanced cryptosystems and concepts are now publicly accessible.