What is cryptography and how safe is it?
Alex Silcock
Cryptography is the mathematical and scientific method of the conversion of plain text into encrypted, unreadable and unintelligible text. Its purpose is to encrypt the text so that it can only be read by the intended recipient. It is used throughout society for the protection of data from theft, alteration of data and simultaneously can be used for user authentication. Cryptography was reportedly first used in 1900 BCE in Egypt to encrypt messages on the tomb of the nobleman Khnumhotep II. After 1900 BCE, it was more commonly used in the first century BCE, in the form of a substitution cipher, by Julius Caesar (Caesar Cipher). The Caesar Cipher shifted the alphabet by a certain number of characters in order to encrypt the message, thus meaning the private key would be the integer of how much to shift the characters in the message by (referring to the alphabet) for it tomake sense. Critical to our everyday lives, cryptography is the foundation of the communication and storage of all sensitive data. Through the use of computing and computer algorithms, this sensitive data can be encrypted to allow for the secure transmission and storage of data, thus transforming it into unreadable strings. Depending on the encryption algorithm, the cypher text can be decoded, using a special key, back into plain text in a readable format. The security of cryptography is based on the complexity and secrecy of the algorithm used for key generation. Encryption is used in most processes carried out online, for example, sending a text file or an email. The extent to which cryptography is secure and safe is dependent on the computational power to crack a key / reverse an algorithm in a reasonable amount of time.
Symmetric key encryption
Symmetric key encryption is the process by which the same 128-bit key (which would take billions of years to guess) is used to both encrypt and decrypt the plain-text, thus meaning that the key needs to be sent to the recipient in order for them to decipher the message. As the processing and computational power of computers advances, symmetric key encryption has become obsolete for encrypting sensitive information due to the low time complexity needed in order to crack the key. Now the more common encryption algorithms used are public and private key encryption (asymmetric) and Digital Signatures Algorithms (DSA). Symmetric key encryption, however, is much faster than asymmetric encryption and can be transferred on the link even if there is a possibility that the data will be intercepted. On the contrary, symmetric cryptosystems have the problem of key transportation, since the key needs to be transmitted to the recipient before the message is transmitted and since every means of electronic communication is insecure, the keys would need to be exchanged in person and thus the message may as well be transferred in person. This is the reason there has been a decline in the use of symmetric key encryption for sensitive data.
Public and private key encryption
Invented in 1997, asymmetric encryption is the process of using two keys ranging from 1024 to 4096 bits, a public and private key in order to encrypt plain-text. The keys are connected and are very large numbers with mathematical properties. The sender encrypts the message with the public key, and the recipient can decrypt the message using their private key. The intermediaries of communication, for
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