What Is Cryptography?


Cryptography uses advanced mathematics, computer science, and communication processes to encode information so only the intended party can read it. It can also be used to prove the integrity of data in storage or during transit between the sender and receiver.


It commonly involves encrypting electronic data by scrambling it into ciphertext and then using a decryption key to restore it to readable format. It can protect against active attacks (in which adversaries read traffic in real-time) and passive attacks.


Cryptography, also known as cryptology, uses codes to ensure that only the person a message was intended for can read and process the information. It’s a necessary form of cybersecurity to keep data and messages private from malicious actors who may try to eavesdrop on or access confidential information.

The term “cryptography” is derived from the Greek words for hidden or secret writing. It’s been around for centuries and continues to be an important part of securing electronic data from interception, hacking and malware attacks. The practice of cryptography, which can be traced back to ancient Egyptian hieroglyphics, combines computer science and mathematics to protect information in transit or at rest.

In the most basic form of cryptography, a message is transformed from its original human-readable format (also known as plaintext) into something that looks like gibberish (ciphertext). The sender has a secret key that’s used to encode and decode the message. The original plaintext is then sent along with the ciphertext to the intended recipient. The recipient then decrypts the ciphertext to read the message.

More advanced forms of cryptography use different algorithms and systems to encrypt and decrypt data. The most popular method, symmetric encryption, uses one secret key for both encrypting and decrypting. The disadvantage to this type of cryptography is that if the secret key is compromised, then a third party can intercept and read the message.


Ciphers are the methods used in cryptography to convert a message or data into something else. They can change the order of bits in 광주흥신소 a byte or replace specific sequences of data with another particular sequence. The result is a cipher text which appears to be random. Modern cyphers are classified into two kinds: stream ciphers which modify a string of data while it is being encrypted and block ciphers which process the message in uniform blocks of a predetermined number of bits. Both use a secret key which must be known by both the sender and the receiver of the message.

Historically, ciphers have been based on simple substitution and transposition. For example, the Caesar cipher attributed to Julius Caesar involves shifting each letter of the alphabet a set number of spaces. This would make D above A, E above B and so on. This is a simple substitution cipher and was used for many centuries.

More sophisticated ciphers take advantage of mathematical concepts such as prime number theory and modulo algebra. They are also based on the idea that it is very difficult to decipher a message when you know its plaintext or its key. These ciphers are typically called block ciphers and they are the foundation of most commercial applications of cryptography for data security such as digital signatures, verification to protect web browsing on the Internet and secure credit card transactions.

Digital Signatures

Digital signatures are an electronic version of a handwritten signature that provides proof of authenticity, integrity and non-repudiation. They also help protect against document forgery, unauthorized changes and loss or destruction. They are based on the industry standard public key infrastructure (PKI) which uses a pair of keys, one private and one public to create a mathematically linked connection between two authenticating parties.

To sign a document, the sender encodes a hash — a fixed length string of letters and numbers — using their private key. This encrypted hash is then attached to the document and sent to the recipient. The recipient decrypts the hash using the sender’s public key and is able to verify that the document was signed by the intended party.

The signature also encrypts the identity of the signatory, making it difficult for threat actors to impersonate the signatories. Additionally, digital signatures provide an audit trail that proves the time, date, and origin of a document. The combination of these features ensures that the documents are genuine and have not been tampered with during transit or storage. This can be vital in ensuring compliance with legal regulations and is often required to protect sensitive information. This is why many governments have passed laws or issued regulations governing the use of digital signatures. The ESIGN Act in the U.S is a good example.

Key Management

Cryptographic keys are one of the most critical components of cyber security. They do everything from data encryption and decryption to user authentication. A single compromised key could allow hackers to expose confidential information or even take control of the entire system. Fortunately, there are best practices that can help you better protect your business’s most valuable assets and prevent costly attacks.

The goal of key management is to safeguard cryptographic keys throughout their life-cycle. This involves implementing systems and policies that deal with the generation, exchange, storage, use, and replacement of the keys at the user level. It also includes a range of other tasks, including key escrow and destruction. Ideally, you will separate keys from the encrypted data so that a breach of one doesn’t compromise the other.

Key management protocols should be centralized or distributed, depending on your security needs and work environment. Regardless of your preference, you should implement a strategy that offers secure backup and recovery. You should also ensure that all keys are properly disposed of at the end of their life-cycle, either by deactivating them or deleting them completely. This will prevent reactivation by attackers and will make any data that has been decrypted using them unusable.

Keeping your company’s data and systems safe is the main reason you should prioritize strong key management protocols. By following these best practices, you can reduce your company’s vulnerability to attack, avoid costly data breaches, and stay in compliance with industry standards and regulations.