What is public key encryption?
Public key cryptography (PKC), also known as asymmetric cryptography, is a mechanism that uses both a private and a public key, as opposed to the single key used in cryptography. symmetry. The use of key pairs gives PKC a unique set of characteristics and capabilities that can be used to solve challenges inherent in other encryption techniques. This form of cryptography has become an important element in modern computer security, as well as a vital component for the development of the cryptocurrency ecosystem.
How does public key encryption work?
In the PKC scheme, the public key is used by the sender to encrypt information, while the private key is used by the recipient to decrypt it. The two keys are different, in that the public key can be shared securely without affecting the security of the private key. Each pair of asymmetric keys is unique, ensuring that a message encrypted with a public key can only be read by the owner of the corresponding private key.
Because asymmetric encryption algorithms produce key pairs that are mathematically linked, the key length is much longer than the key pairs produced by symmetric encryption. This longer length - typically between 1,024 and 2,048 bits - makes calculating the private key from the public key extremely difficult. One of the most common algorithms for asymmetric encryption in use today is called RSA. In the RSA scheme, keys are generated using a modulus that multiplies two numbers (usually two large prime numbers). To put it more simply, the module generates two keys (a public key that can be shared and a private key that needs to be kept secret). The RSA algorithm was first described in 1977 by Rivest, Shamir, and Adleman (RSA is a combination of the first letters of these three) and remains a key component of public-key cryptosystems.
PKC - Cryptographic tool
Public key cryptography solves one of the long-standing problems of symmetric algorithms - the problem of communication of the key used for both encryption and decryption. Sending the key over an insecure connection risks exposing any messages encrypted with the shared key to a third party. Although there are cryptographic techniques (such as the Diffie-Hellman-Merkle key exchange protocol) to solve this problem, the risk of attack is still possible. In contrast, with public key cryptography, the key used for encryption can be securely shared across any connection. As a result, asymmetric algorithms provide a higher level of protection than symmetric algorithms.
Application to create digital signatures
Another application of asymmetric encryption algorithms is data authentication through digital signatures. Essentially, a digital signature is a hash created using data in a message. When a message is sent, the recipient can verify the signature using the sender's public key as a way to authenticate the source of the message and to ensure that the message is not forged. In some cases, digital signatures and encryption are applied in combination with the hash itself being encrypted as part of the message. However, it should be noted that not all digital signature schemes use encryption techniques.
Restrictions
Although it can be used to enhance computer security and provide verification for message integrity, PKC has some limitations. Because of the complex mathematics involved in encryption and decryption, asymmetric algorithms can be quite slow when forced to process large amounts of data. This type of cryptography also relies heavily on the assumption that the private key will be kept secret. If a private key is accidentally shared or exposed, the security of all messages encrypted with its corresponding public key is compromised. Users can also accidentally lose their private keys, in which case they cannot access encrypted data.
Public key encryption applications
This type of cryptography is used by many modern computer systems to provide security for sensitive information. Email, for example, can be encrypted using public key encryption techniques to keep the content secret. The Secure Sockets Layer (SSL) protocol helps secure connections to websites that may also use asymmetric cryptography. PKC systems have even been used as a means of providing a secure electronic voting environment capable of allowing voters to participate in elections from their home computers.
PKC also has a prominent presence in blockchain technology and cryptocurrency. When a new cryptocurrency wallet is set up, a key pair is generated (public key and private key). The public address is created using a public key and can be securely shared with others. Private keys, on the other hand, are used to create digital signatures and verify transactions, and therefore, must be kept secret. Once a transaction has been verified by confirming the hash contained in the digital signature, it can be added to the blockchain ledger. The digital signature verification system ensures that only the person with the private key linked to the respective cryptocurrency wallet can withdraw funds. It should be noted that asymmetric ciphers used in cryptocurrency applications are different from those used for computer security purposes. For example, Bitcoin and Ethereum use a specialized cryptography called the Elliptic Curve Digital Signature Algorithm (ECDSA) to verify transactions.
From computer security to verifying cryptocurrency transactions, public key cryptography plays a vital role in securing modern digital systems. By using public and private keys in pairs, asymmetric encryption algorithms solve the basic security problems presented by symmetric encryption. Although PKC has been in use for many years, new uses and applications are regularly developed for it, especially in the blockchain and cryptocurrency sector.
