If you think of a particular object having a distinct feature like a diamond amongst stones (or gems), think of public-key cryptography (PKC) in that light when you think about the kinds of cryptography. This cryptography is unique because it is now a vital component of today’s modern security on computers, and it is an integral part of the cryptocurrency ecosystem.
You can also regard public key cryptography as asymmetric cryptography. This framework uses private and public keys compared to symmetric cryptography that uses a single key. These key pairs bestow the algorithm’s unique characteristics and capacity to solve problems associated with other cryptographic models.
How Public Key Cryptography (PKC) Works
For every PKC, it is regarded as a tool to conceal certain information from the general public between two parties. You can call this kind of information concealment “encryption.” As such, you can call PKC an encryption tool.
As a sender, you encrypt information using the public key, and your recipient uses the private key to decrypt the same information. These two keys are different. As a result, you can share the public key without compromising the private key security. Every asymmetric key is unique. As a result, your recipient can only read an encrypted message if they possess the corresponding private key.
When you compare the key length of asymmetric and symmetric cryptography, you will realize that asymmetric cryptography’s keys are more extended than symmetric cryptography’s keys. That’s because the encryption keys generated by the algorithms are mathematically linked. This length makes it almost impossible for you to create a private key from a public key.
Each key has a length between 1,024 bits and 2,048 bits, and the RSA algorithm is used for asymmetric encryption. And it is a standard algorithm. The RSA algorithm uses a modulus that multiplies two numbers to generate keys. Most times, these two numbers are prime numbers. The two keys generated have one you can share (the public key) and the other you cannot share (the private key).
Modeling PKC to Encrypt
When you take a critical look into the function of PKC, you will realize that it solves the preexisting problems associated with symmetric algorithms. One major problem of symmetric algorithms is key communication. That is, how you can send the encryption and decryption keys over a secure network without being exposed to a third party. This exposure can lead to cyber theft and cause a compromise.
But PKC is solving this communication problem. You can share the encryption key via a secure connection. This presents users with a high level of key protection without the fair of compromisation.
Digital Signatures Generator
Think of digital signatures as hashes created from data existing in a message. Thus, asymmetric cryptography algorithms allow data authentication via digital signatures. With this method, the recipient can confirm if a piece of information has not been tampered with by checking the sender’s public key.
Likewise, this authenticates the message source. Meanwhile, the hash can also be a message part. This means that digital signatures and encryption are used at the same time. However, you might not find encryption techniques embedded in all digital signatures.
Limitations of Public Key Cryptography
It is natural to think of PKC as the ultimate solution to encryption and decryption. While this may be true, you must acknowledge that PKC has its flaws too. Thus, we will examine some of the limitations associated with PKC.
The first limitation is the slow speed of data processing. When using asymmetric algorithms to process a large chunk of data, the algorithm can be slow. This is due to the complex nature of the mathematical operations.
Another limitation is the problem associated with sharing problem. Initially, you need the private key to open the encrypted message. When it falls into the wrong hands, the security of the encrypted messages might undergo a compromise.
The last limitation is associated with key loss. When you accidentally lose your private key, it becomes impossible for you to access the encrypted message. That means you literally cannot read the message, and whoever retrieves it will access the information.
Other Utilizations of Public Key Cryptography
PKC is used by several computer systems today to secure delicate information such as emails to make them confidential. Likewise, the secure sockets layer (SSL) protocol that allows internet users to establish secure connections with their websites uses asymmetric cryptography.
Another use includes PKC embedded in voting systems that will allow voters to conduct their voting right via a secure e-voting channel. As a result, anyone can vote in an election using computers from their home.
Widespread use of PKC is in blockchain and cryptocurrency technology. When you create a new wallet, key pairs are automatically generated. These are the private and the public keys. The public key generates the wallet address, which a user can share with anybody. But the private key is used to create digital signatures to verify transactions. As such, private keys must be kept confidential.
As soon as you verify the transaction, the transaction will be on the blockchain ledger when you confirm the hash in the digital signature. This means that digital signatures make it only possible for the private key holder to move funds from a corresponding wallet.
However, it is pertinent to understand that the asymmetric cryptography for crypto applications and computer security systems is different. For instance, the Elliptic Curve Digital Signature Algorithm (ECDSA) is what Bitcoin and Ethereum networks use. Meanwhile, this algorithm generates digital signatures without encryption.
There would have been lots of cybersecurity breaches without public-key cryptography. Likewise, crypto transactions may lead to cyber-fraud without the strict public key cryptography embedded in the network. With the use of PKC, the fundamental problems associated with symmetric algorithms get solved.
As much as PKC has had different applications for several years, the blockchain and crypto ecosystem makes it possible to witness innovative uses and applications built for this type of cryptography.