Cryptography
Cryptography is the art of creating and deciphering codes, ciphers, and other methods of protecting information from unauthorized access. The word "cryptography" comes from the ancient Greek words "kryptos" and "graphein", meaning "hidden" and "writing" respectively. It describes the essence of cryptography - to encrypt information in such a way that it remains hidden from prying eyes.
The study and application of cryptography has existed for many centuries, dating back to ancient civilizations. The use of numerical encoding in cryptography can make the process of creating and deciphering codes more efficient and secure.
One of the well-known ciphers, the Caesar cipher, uses letter shifts by a certain number of positions in the alphabet to create a ciphered message. This can be easily implemented using numerical encoding. Additionally, in cryptography, mathematical operations with numbers can be used to encrypt messages, for example, using the Vigenere cipher, where each letter is encrypted using a sequence of key numbers.
However, along with technological advancements and possibilities, cryptography has become more complex and sophisticated. Modern encryption methods use algorithms and keys with high degrees of protection, such as the RSA algorithm, which uses multiple prime numbers to create keys. These methods can provide reliable protection for digital data and ensure the confidentiality of important information.
Thus, cryptography is an important tool for information protection and data security. The use of numerical encoding in cryptography can make the process of creating and deciphering codes more efficient and secure, while modern encryption methods can provide reliable protection for digital data and ensure the confidentiality of important information.
Cipher
A cipher is a system of transforming information into an unintelligible form so that it can be transmitted over an unprotected communication channel without the risk of interception or understanding by an unauthorized recipient. Encryption can be used to protect the confidentiality, integrity, and authenticity of data, as well as to ensure the security of the system as a whole. There are many different encryption methods that can be used to achieve these goals, including symmetric encryption, asymmetric encryption, and hashing.
To be a cipher, a text must possess several characteristics:
Obscurity: The encrypted text must be unreadable to an unauthorized recipient, either appearing as a meaningless string of characters or containing information that can only be understood with a special key. Key: Encryption must use a key that allows the encrypted information to be decrypted. The key can be common for the sender and recipient (symmetric encryption) or different for each of them (asymmetric encryption). Complexity: Encryption must be complex enough to resist easy decipherment without knowledge of the key. The more complex the cipher, the more secure it is considered. Reliability: Encryption must be reliable enough to resist attacks of various types, such as key brute-forcing, frequency analysis of characters, and other cryptanalytic methods. Ease of use: Encryption must be user-friendly for both sender and recipient, so they can easily transmit and receive encrypted messages.
