A Guide to Public Key Infrastructure 

What is Public Key Infrastructure ?
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What is Public Key Infrastructure (PKI)?

Public key infrastructure is a system that facilitates the secure exchange of data over a network. It is an encryption method based on asymmetric cryptography that uses two different keys to encrypt and decrypt data.

Public key cryptography is an approach to provide encryption and decryption of data (into ciphertext and plaintext, respectively) based on a key pair consisting of a public key and a private key. Whitfield Diffie and Martin Hellman invented the public/private-key encryption method in 1976.

How does PKI work?

PKI is a set of digital certificates used to authenticate or encrypt messages. It is the foundation for internet commerce and transactions.

It works because of asymmetric encryption, which relies on two keys, sometimes called public and private keys. The public key is publicly known; the private key must be kept secret. PKI provides an enhanced level of security by using digital signatures to sign messages for verification purposes.

What are the components of PKI?

Public Key Infrastructure is a set of different components designed to protect and identify data in a digital environment. They are composed of two major components: the certificate authority and the registration authority.

The key component in this system is the certificate authority which issues certificates to identify public keys that belong to digital certificates. It also regulates how public keys are registered, assigning them to a specific owner or entity. The registration authority then issues certificates that authorize them with an encryption algorithm, guaranteeing that they are trustworthy and authentic.

What are Digital Certificates?

Digital certificates are electronic documents used to validate people's identities or software. They are often used for online transactions like sending money, transferring data, logging into accounts etc. Digital certificates can be issued by individual organizations or a third party. The most common type of digital certificate today is the X.509 certificate issued by a Certificate Authority (CA).

Digital certificates consist of three components: public key infrastructure (PKI), private key and digital certificate. A PKI is a system that ensures that data can only be accessed by those who have the appropriate private key and public key pair. The private key remains with the person or organization that owns it, while the public key goes out to potential recipients - like recipients of an email message or other information, websites, etc.

What is a Certificate Authority?

A Certificate Authority (CA) is an organization that issues digital certificates to help establish secure communication between two entities on the internet. A PKI includes Certificate Authorities, root certificates, and certificate chains.

Certificate Authorities are organizations that issue digital certificates to help establish secure communication between two entities on the internet. An organization's CA may be responsible for issuing the certificates issued by another CA if it has been outsourced or delegated. 

What is a Registration Authority?

A Registration Authority (RA) is responsible for validating the identity of public key holders. It also participates in the issuance and management of certificates.

A Registration Authority provides an organization with a means to identify its employees, members, or customers and issue credentials. It usually does so by storing the digital certificates issued by a Certificate Authority.

What type of encryption does PKI use?

PKI uses both symmetric and asymmetric encryption to encrypt data.

The use of symmetric encryption allows one key to encrypt and decrypt data. This type of encryption is easier than asymmetric but less secure because the key can be compromised if it falls into the wrong hands. Asymmetric encryption can be used in two keys - one public and one private. The public key can be shared while the private key must remain secret; this type of encryption requires more computational power than symmetric, so it's not as efficient for large amounts of data, but it's more secure due to its mathematical properties.

Symmetrical encryption is a type of encryption used to decrypt and encrypt data symmetrically. It only requires a single key to encrypt and decrypt data.

Asymmetric encryption uses different keys for encoding and decoding the data. One key encrypts the data while the other decrypts it. This allows two people to communicate securely when they don't know each others' public key beforehand since it does not require any prior knowledge of who they are communicating with to transmit information securely back-and-forth.

What is the difference between Public Key and Private Key?

A public key is a mathematically generated sequence of numbers used in encryption algorithms to encrypt data to keep it secure. These numbers are generated for you by an authorized third party, usually a certificate authority.

A private key is the reverse of the public key. It is mathematically generated and can be used to decrypt encrypted information with the corresponding public key. In other words, if you have a private key, you can decrypt any message that was encrypted using your corresponding public key. You should never share your private keys because they will allow somebody to impersonate you and access encrypted information using your corresponding public key.

Authentication & Encryption in Public Key Infrastructure

Public Key Infrastructure (PKI) is a security system that uses encryption and digital certificates to authenticate and encrypt data. Authentication helps ensure that the person or computer is who they say they are by validating their identity. Encryption protects the information from being read by others by encoding it with a key that only authorized people know.

How do you generate a Public Key?

To generate a public key, you need to know two things; an algorithm and a private key. The algorithm is the math for encrypting information, whereas the private key is the information used to decrypt it. The public key is shared with the world, whereas the private key is kept secret.

What is the difference between PKI and SSL?

PKI and SSL are both encryption methods widely used in the IT world.

PKI is a standard used to create, manage, store, distribute, and revoke digital certificates. These certificates are issued by a trusted third-party Certificate Authorities (CA). There are three different types of PKI: web PKI, enterprise PKI and cloud PKI.

SSL stands for Secure Sockets Layer and is a protocol designed to provide security for data exchanged over a computer network such as the internet. It does so by encrypting data between an application running on one device to another application on another device, such as your browser or email client.

Why is PKI important?

PKI is important for the following;

  • encrypting and protecting data from unauthorized access.
  • providing confidentiality, integrity, and authentication and for non-repudiation. 
  • allowing encryption and decryption capabilities to secure data in transit.

Advantages of PKI

The advantages of PKI are that it provides reliability, scalability, and efficiency. The only disadvantage is that it requires an up-front investment in hardware and software.

Where is PKI used?

With the increase in data breaches, internet security is a constant concern. The way to stay secure from malicious actors is by using cryptography. PKI is used to encrypt sensitive personal data such as your Social Security Number (SSN), credit card information, phone numbers, addresses, etc. ensuring your private information doesn’t get misused.

It offers protection against unauthorized access and is used in many industries such as finance, healthcare, law enforcement, and even social media

Our view on the future of PKI

PKI is crucial in enterprise IT to secure interactions between customers, teams and organisations and is used in countless situations. However, there is certainly room for improvement. The increasing complexity of work environments demand different things in order to achieve the desired results and it’s doubtful that traditional PKI alone can provide the solution. We believe that certain aspects of blockchain can be used to improve PKI. For example, PKI currently relies on a centralized CA authority, which can be a risk for security. Furthermore, other qualities of blockchain, like immutability and transparency of data, can improve security since they prevent the changing of important data.

At LifeHash, we believe that ultimately the future of the web is decentralized and all our solutions are built in such a way that they have decentralized infrastructure at the core.



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