Cryptography comes from the Greek language by combining two words, namely kryptos and graphein. Kryptos means hidden or secret, while graphein means writing. The literal meaning of cryptography is writing in secret to convey messages that need to be kept confidential.
In Indonesia, cryptography or cryptology is also called sandisastra. The purpose of cryptography is to carry out various communication efforts between individuals or groups safely without the presence of unwanted parties. Another one of its goals is to analyze communication that is difficult to understand.
What is Cryptography?
Criptography has another meaning, namely a science of encryption techniques of the original text (plaintext) which is scrambled using an encryption key so that the original manuscript is turned into a hard-to-read script (ciphertext) by a party who does not have a decryption key.
Cryptography develops in line with technological advances. According to the chronology of the time, cryptography can be divided into two understandings, namely classical cryptography and modern cryptography. Both of these understandings depend on the use of cryptological analytical and messaging tools.
What is classical cryptography? Classical cryptography is cryptography in its manufacture and analysis in no way involving computers or machine devices. The tools used are concerned with the use of paper, pens, stones, and other tools that are not classified as modern machine tools at all.
The distinctive feature of classical cryptography is that it is more based on characters, both written characters and message characters. Another characteristic is the use of tools that are still fairly traditional because at the time they appeared they were not familiar with computers. That’s how classical cryptography works.
All cryptographic algorithms (chippers) of classical cryptography are included in a symmetric cryptographic system. The encryption techniques in classical cryptography are all the same as the encryption keys. That is, to understand a hidden text can be done in the same way as when it was created.
History of Cryptography
Cryptography according to historical records has existed since the heyday of Greece or approximately 400 BC. The tool used to create hidden messages in Greece at that time was called the Scytale. Scytale is a cylindrical rod with a combination of 18 letters.
In Roman times, under the rule of Julius Caesar, the use of cryptography was increasingly intense because of considerations of state stability. Although the technique used is not as complex as the Greek, it is quite difficult to understand cryptographic messages from the Roman period.
Based on the historical aspects of cryptography above, both classical and modern cryptography have the same great and undeniable principle, namely that the purpose of cryptography is security. That is the service that cryptography provides regardless of which time it was created.
Through the security services provided by this type of cryptography, the confidentiality and authenticity of various important texts can be maintained, so that the corresponding parties can trust each other. Unless the cryptographic technique is leaked to unwanted parties.
It seems that you need to know as a basis for an initial understanding of cryptography, namely algorithms in cryptographic science. Algorithms themselves have the meaning of steps or methods that are arranged systematically. When embedded in “cryptography”, then the meaning of cryptographic algorithms is a logical step to hide the message.
There are three basic functions in cryptographic algorithms, among others; encryption, decryption, and keys. Encryption means the process of hiding message data, converting plaintext into ciphertext. While decryption is the opposite of encryption, it aims to understand the message, and the key is a technique used for both encryption and decryption.
In the era of modern cryptography, cryptography does not have to be large and go through stages that are difficult to understand. Even in the modern era, cryptography can be presented in a portable way, just like applications that use cryptography.
An application made for cryptography means a program that allows encryption and decryption when securing a message in desktop or mobile data.
This application is usually used to secure the device and the contents in the device itself by locking it using a cryptographic algorithm method. This kind of practice is very familiar in modern cryptography because of the facilities and infrastructure that are fully supported.
The use of this cryptographic application makes device security multi-layered. For someone who intends to open the device, they must pass through several series of keys that have been provided to secure the device.
Someone who makes use of cryptography in an application obviously has a very high level of privacy. For the sake of confidentiality over privacy, applications that use cryptography are deemed important to use. Having multiple layers of security will leave people with bad intentions exhausted when unpacking.
There are lots of applications that provide cryptographic services, in fact, each application is equipped with cryptographic tools, for example the WhatsApp and Telegram applications. Both secure users through encryption keys that are quite complicated and tight for the sake of protecting user privacy.