Public Key Cryptography is very important in the world of the internet to protect your data and provide security. The level of security of the information data that can be used varies depending on the use of information.
In e-commerce data information that is used in exchange has a high level of security concern in order to prevent theft and unauthorized access.
One technique of securing data information on the internet is called Asymmetric cryptography. A cryptographic algorithm contains mathematical functions which are used in the encryption and decryption process.
Cryptology is the science of studying a safe way of communication that includes cryptography and cryptanalysis. Cryptography is a branch of cryptology regarding the design of algorithms for encryption and decryption processes which ensures confidentiality and authenticity of a message.
Table of Contents
There are 3 objectives of cryptography namely confidentiality, integrity, and Authentication. Let’s discuss each.
Confidentiality: Confidentiality of provision that is used to secure the information content from unauthorized persons and allow access to the legitimate person.
Data integrity: data integrity is a provision relating to the security of unauthorized data changes. To maintain data integrity the system must have the ability to detect when attempted unauthorized including but not limited to insertion, deletion, and substitution of data.
Authentication: Authentication is a provision related to identification where the information sent and that must be authenticated.
Cryptography is a method which is used to secure the information from a third party during the communication process. The word is composed of two Greek terms, the term Kryptos meaning “hidden,” and Graphein, meaning “to write.
In blockchain technology cryptography is used in the protection of privacy and security of data. The methods included in cryptography are symmetric and asymmetric encryption.
There are 4 terms in cryptography that need to be understood, so let’s discuss them.
Encryption: It is the technique that is used to convert normal text into some coded form to protect messages from intercepting.
Key: The element that is used by the sender to decode the message at the receiver’s side sends its public key to verify the integrity of the message. These are two types of public and private keys.
Decryption: It is a technique to decrypt the coded message in plain text format with the help of keys.
Cipher: its a function that is used in converting plain text into some random sequence of bits called ciphertext.
Public key cryptography
Asymmetric Key Cryptography: This technique or encryption method uses two key pairs, one for encryption and one decryption key also called public key and private key respectively.
The asymmetric key algorithm generates a key pair which includes a private key and a unique public key. It is also known as public-key encryption. Asymmetric key cryptography is highly scalable.
In Asymmetric key cryptography, the key exchange process is quite simple, here one member produces a secret key and encrypts it with the public key of the receiver then the receiver easily decrypts it with their private key for the establishment of a secure connection.
For example, if Alice generates a private key and a corresponding public key, the public key is known by anyone but Alice must keep the private key secret.
Characteristics of public key encryption
In public key systems, there are two keys: a public key and a private key. You can use either one to encrypt data, and the other key is used to decrypt it. The public key is shared with anyone who needs it, allowing them to encrypt data or verify signatures.
The private key, however, is kept secret and is used by its owner to decrypt data or create digital signatures.
RSA (Rivest–Shamir–Adleman) is the most common public-key system. Its security is based on the fact that it’s very hard to find the prime factors of a large number, which is essential to breaking the encryption.
For example, as shown in the figure below, public keys for every user are present in the register. If B wants to send the confidential message to C, then B must encrypt the message using the public key of c. when c receives the message from B and decrypts it using its private key. No other parties can decrypt the message because only c has a private key.
Component of public key encryption
Plain text: This is the text or message which is in a simple format. This message is fed as input in the encryption algorithm.
Cipher text: This is the output of an encryption algorithm. It is in the encrypted form so it is unreadable.
Encryption: this is the method of converting plain text to cipher text.
Decryption: when cipher text is passed as input combined with a private key it produces the original result.
Public and private key: one key is used for encryption and the other is used for decryption.
Application of public key encryption
Encryption is employed in cryptography to safeguard information and communication on a network from unauthorized access and disclosure.
The immutability aspect of cryptography is instrumental in blockchain technology, ensuring secure linking of blocks and maintaining the integrity of stored data. It also prevents attackers from generating valid signatures for unauthorized queries based on previous queries and their signatures.
Cryptography enhances transaction record keeping by encrypting data and enabling data access through public and private keys. The tampering of data through cryptographic hashing is not feasible, thereby bolstering blockchain security.
With cryptography, transactions become irreversible, instilling confidence in the accuracy of the digital ledger and enabling secure recording of limitless transactions.
Digital signatures provide non-repudiation services, guarding against denial of messages by the sender. This is attributed to collision resistance, as each input value has a unique hash function, preventing any conflict between sent messages.
Cryptography plays a crucial role in computer security, particularly in the creation and storage of passwords. When users log in, their passwords are hashed and compared to the previously saved hash, ensuring encryption and preventing unauthorized access to the password database.
Digital currencies like Bitcoin utilize encryption to secure transactions and prevent fraud. Complex algorithms and cryptographic keys safeguard these transactions, making it highly challenging to tamper with or counterfeit them.
Cryptography is utilized to provide web browsing security, safeguarding users against eavesdropping and man-in-the-middle attacks. The Secure Sockets Layer (SSL) and Transport Layer Security (TLS) protocols employ public key cryptography to encrypt data exchanged between the web server and the client, establishing a secure communication channel.
Authentication protocols make extensive use of cryptographic techniques to verify a user’s identity and ensure they have the necessary access privileges for resources. Additionally, the storage and verification of electronic signatures are reliant on cryptography for security.
Cryptography also plays a vital role in securing two-way communications such as video chats, instant messages, and email. Even with basic encryption, messages are guaranteed to be viewed only by the intended recipients. End-to-end encryption offers a high level of protection and privacy for consumers and is frequently employed in messaging apps such as WhatsApp and Signal.