The book is distributed as part of the Hestart project. The author shares with the young readers of the science site the basics of encryption
by Stav Alber
In the digital world, where information flows constantly between computers and networks, the need to protect sensitive information from prying eyes has become more essential than ever. Encryption is the main tool that allows us to maintain confidentiality, verify identities and manage secure communications. Encryption is not only a part of history, it is an integral part of our lives today - it protects us when we browse the Internet, shop online, and even use mobile apps.
The enormous importance of encryption is what led me to write a children's book, which makes the world of encryption accessible to the future generation! The book is available here – https://headstart.co.il/
But in the meantime, in order to better understand the world of encryption, we will examine two major algorithms.
Symmetric encryption: one secret key
Imagine a black box with a secret message inside. To lock and unlock the box, a single key is needed. This is the basic principle of symmetric encryption: the sender and receiver use the same secret key to encrypt and decrypt the information.
The sender uses the secret key to turn the original information into encrypted text, unreadable by a person who does not have the key. It then sends the ciphertext to the recipient, who uses the same key to decrypt the message and reveal the original message. This method, similar to a single key that opens a secret door, ensures that only the person holding the key can access the information.
Many examples of the use of symmetric encryption exist in everyday life. Many programs allow you to encrypt files on your computer using a password, which is actually the secret key. Home Wi-Fi networks also often use symmetric encryption to secure the communication between the devices, as do ATMs when withdrawing cash, which protect the communication between the ATM and the bank card.
The main advantage of symmetric encryption is its speed and efficiency, which makes it particularly suitable for encrypting large amounts of information. In addition, the algorithms are relatively simple to implement. However, the main drawback is the need to transfer the secret key securely. If the key falls into the wrong hands, the encrypted information will be exposed.
Asymmetric encryption: two keys, many options
Asymmetric encryption, also known as public key encryption, is based on a revolutionary idea: the use of two different keys - a public key and a private key.
Each user has a pair of keys: a public key, which is accessible to everyone and can be used to encrypt information intended for this user's eyes, and a private key, which is kept secret by the user and is used to decrypt information encrypted with his public key.
You can imagine writing mail with two slots: one slot for inserting letters (public key) and a separate, locked slot, for taking them out (private key). Anyone can insert a letter through the public slot, but only the owner of the key to the box can take out and read the letters.
This method is widely used in a variety of applications, including a digital signature that allows to verify the sender's identity and ensure the integrity of the document, electronic commerce that allows for secure online transactions, and secure internet communication.
The prominent advantage of asymmetric encryption is the security of the keys. There is no need to transfer the private key, which reduces the risk of theft. In addition, this method enables identity verification, that is, verifying the identity of the sender. However, the algorithms are more complex to implement and asymmetric encryption is slower than symmetric encryption, and therefore less suitable for encrypting large amounts of information.