A public key infrastructure consists of software and hardware elements that a trusted third party can use to establish the integrity and ownership of a public key. A certification authority is called by the trusted party and establishes the integrity by issuing signed binary certificates that affirm the identity of the certificate subject and bind that identity to the public key contained in the certificate. I think this is extremely important in maintaining the security of the key and makes sure that the integrity of the data is not compromised.
Reading about X.509 public key infrastructure was certainly a new thing for me. Its the standard that identifies the requirements for robust public key certificates. It also covers asymmetric cryptographic techniques and how identities are paired with cryptographic key pairs. X.509 certificates are useful for many tasks, including:
-> Authenticating clients, servers, and other devices as well as individuals and organizations.
-> Ensuring the integrity of emails, software and code, digital documents, and various data transmissions.
-> Securing data exchanges for websites and email communications using encryption. This helps to protect data both while it’s in transit and at rest.
What I gleaned from the two articles is that the public key infrastructure (PKI) system helps in eliminating spoofing attacks where an attacker could pose as one of the two communicating parties and replace their public key with its own public key. With PKI the communicating parties can trust a certification authority (CA) to have reasonably verified the identities of those intending to securely communicate. The CA issues a digitally signed certificate that is in the X.509 format and it contains information such as the name of the certificate owner, certificate validity, issuer name, serial number, etc.
Hi Nishant ,
Yes, that is accurate. By allowing a dependable third party (the CA) to confirm the identities of people interacting, PKI and X.509 aid in building trust and ensuring secure communication between parties. The CA issues X.509 certificates with vital details about the certificate owner, helping to thwart spoofing attempts. By using this approach, communicating parties can establish secure communication and confirm the validity of each other’s certificates.
My thoughtful read on these articles is that a certifying authority can employ a public key infrastructure (PKI), which consists of hardware and software components, to verify the authenticity and ownership of a public key. The certification authority, registration authority, certificate database, certificate store, and key archive server are the components of PKI. In essence, it entails the involvement of dependable third parties who use the issuance of digital certificates to confirm the identity of the parties seeking to engage in secure communication. X.509 certificates are primarily used to confirm the legitimacy of a website, a person, or a company.
Generally, I think CA is the authority of certificates and an authoritative, trusted, and impartial third-party organization with authoritative features in PKI applications, and it is also the core of the PKI system and the trust foundation of PKI, which manages the whole life cycle of public keys. If the CA stops its external service, the whole PKI system may be paralyzed. Therefore, the security and stability of CA itself are of immense importance.
PKI: system that enables secure communication over internet through use of public and private keys. It also enable the management of digital certificates.
X.509: It is a standard for encoding digital certificates that are used in PKI systems. X.509 public key certificates contain information about identity of certificate holder, their public key, digital signature of certificate issuer. They are used to verify authenticity of party’s public key. These certificates are used in many applications like SSL/TLS encryption for web traffic, email encryption and digital signatures, and secure authentication of users and devices in a network.
Both PKI and X.509 certificates are critical in ensuring secure communication. They play vital roles in securing transactions, establishing trust between parties, protecting sensitive data.
Public Key Infrastructure (PKI) is a system used to verify the identity of users and devices in the digital world. It involves the use of digital signatures from trusted parties to certify that a specific cryptographic key belongs to a particular user or device. X.509 is a standard that defines the format of these public key certificates and they are commonly used in many internet protocols such as TLS/SSL (which is used for secure browsing through HTTPS) as well as in offline applications like electronic signatures.
Public Key Infrastructure (PKI) is used to secure communications and authenticate the identity of individuals and organizations. Using public key encryption, it provides a secure method of exchanging sensitive information over public networks whose security is not verified, such as the Internet. x.509 certificate is a digital document that defines the format and structure of the digital certificate used in PKI. A digital certificate is a data file that contains information about the identity of an individual, organization, or device. X.509 certificates are used to authenticate the identity of entities involved in secure communications and transactions, such as encrypted communications based on SSL/TLS.
Public Key Infrastructure is one of the concept or areas I have been struggling to grasp how it works and it’s main purpose. However, the article shed some light to me by explaining some elements involved within the process and their descriptions.
Certification Authority
Acts as the root of trust in a public key infrastructure and provides services that authenticate the identity of individuals, computers, and other entities in a network.
Registration Authority
Is certified by a root CA to issue certificates for specific uses permitted by the root. In a Microsoft PKI, a registration authority (RA) is usually called a subordinate CA.
Certificate Database
Saves certificate requests and issued and revoked certificates and certificate requests on the CA or RA.
Certificate Store
Saves issued certificates and pending or rejected certificate requests on the local computer.
Key Archival Server
Saves encrypted private keys in the certificate database for recovery after loss.
One key takeaway is the elements that PKI (public key infrastructure) consists of the following:
1. Certification Authority – acts as the root of trust.
2. Registration Authority – certified by a root CA to issue certificates for specific uses permitted by the root.
3. Certificate Database – saves certificates requests and issued and revoked.
4. Certificate Store – saves issued certificates and pending or rejected certificate requests on the local computer.
5. Key Archival server – saves encrypted private keys in the database for recovery after loss.
I was not familiar with the Key Archival Server so it was good to know about it. Also, I had previously read about Online Certificate Status Protocol (OCSP) as online implementation of Certification Revocation List (CRL). The two other elements – Certification Database and Certificate Store in the article might be Microsoft’s way of implementing an OCSP system.
PKI is a chain of trust. An individual certificate is trusted because it can be tracked up to a trusted issuer that I can trust. I know that the certificate itself is legitimate because we can trust the x509 standard and the cryptography it is based on to prevent alteration or modification of a certificate. I do not have to trust the certificate authority that issued the certificate directly, so long as I trust one of that authority’s roots.
The analogy that I like to use for PKI is the driver’s license or passport. Anyone can put a name and a picture on a plastic card, but I won’t trust it unless I trust the issuer. I don’t have to know you or perform a background check on you to trust your name is what you say it is if i can see your government ID (certificate) because i can trust the State (Root CA) that issued it to you to confirm your identity. Similarly, Costco employees will trust a Costco card because they trust that Costco (intermediate CA) checked your ID (issued by a trusted root) before giving you the Costco card (intermediate certificate), but if you show a Sam’s Club card, they won’t accept it because they cannot trust it (different intermediate CA with no common root of trust).
Hi David,
I like your analogy. It helped me better understand the relationships between the key elements of PKI. Since Costco and Sam’s Club are registered by different institutions, we cannot confirm whether they use the same root for identity verification, the two authentications cannot communicate with each other. Thank you for sharing.
One key takeaway public key cryptography relies on a public and private key pair to encrypt and decrypt content. The keys are mathematically related, and content encrypted by using one of the keys can only be decrypted by using the other. The private key is kept secret. The public key is typically embedded in a binary certificate, and the certificate is published to a database that can be reached by all authorized users. On the other hand, an X.509 certificate contains an identity and a public key. It binds an identity such as an individual or hostname to a public key with a digital signature. The signature is either made by a trusted certificate authority (CA) or is self-signed. Some digital certificates can also be automated.
I found the chart that outlines elements of PKI to be extremely helpful.
Certification Authority:
Acts as the root of trust in a public key infrastructure and provides services that authenticate the identity of individuals, computers, and other entities in a network.
Registration Authority:
Is certified by a root CA to issue certificates for specific uses permitted by the root. In a Microsoft PKI, a registration authority (RA) is usually called a subordinate CA.
Certificate Database:
Saves certificate requests and issued and revoked certificates and certificate requests on the CA or RA.
Certificate Store:
Saves issued certificates and pending or rejected certificate requests on the local computer.
Key Archival Server:
Saves encrypted private keys in the certificate database for recovery after loss.
Understanding these elements will help you understand the hierarchy of PKI (Certification Authority/Registration Authority), in addition to how they are stored/safeguarded.
Public Key Infrastructure (PKI) provides a framework of encryption and data communications standards used to secure communications over public networks. At the heart of PKI is a trust built among clients, servers and certificate authorities (CAs). This trust is established and propagated through the generation, exchange and verification of certificates
Understanding the X.509 certificate, which is fully defined in RFC 5280, is key to making sense of those errors. Unfortunately, these certificates have a well deserved reputation of being opaque and difficult to manage. With the multitude of formats used to encode them, this reputation is rightly deserved.
An X.509 certificate is a structured, binary record. This record consists of several key and value pairs. Keys represent field names, where values may be simple types (numbers, strings) to more complex structures (lists). The encoding from the key/value pairs to the structured binary record is done using a standard known as ASN.1 (Abstract Syntax Notation, One), which is a platform-agnostic encoding format.
As mentioned in the Public Key Infrastructure, the public key infrastructure (PKI) consists of the software and hardware elements that a trusted third party can use to establish the integrity and ownership of a public key. The trusted party that signs the document that associates the key with the device is called a Certificate Authority (CA) and typically verifies that the public key has not been tampered with or corrupted during transmission by issuing a signed (encrypted) binary certificate.
The article discusses how organize a secure method of information exchange between individuals. For this purpose, asymmetric-key cryptography is used. The key pair consists of one public and one private key to encrypt and decrypt content. Both keys are mathematically related. Individuals involved in the process of communication should distribute the public key but must keep the privet key secret. Message encrypted by using one of the keys can be decrypted by using the other according to the following scheme. Participant 1 and Participant 2 have their own key pairs. They have kept their private keys securely to themselves and have sent their public keys directly to each other. Participant 1 uses Participant 2’ s public key to encrypt the message and sends it to him/her. Participant 2 uses his/her private key to decrypt the message. However at least one obvious concern Participants must have about the public key they used to encrypt the message. That is, they cannot know with certainty that the key Participant 1 used for encryption actually belonged to Participant 2. It is possible that another party monitored the communication channel between Participants and substituted a different key. The public key infrastructure concept has evolved to help address this problem and others. A public key infrastructure (PKI) consists of software and hardware elements that a trusted third party can use to establish the integrity and ownership of a public key. The trusted party, called a certification authority (CA), typically accomplishes this by issuing signed (encrypted) binary certificates that affirm the identity of the certificate subject and bind that identity to the public key contained in the certificate. The CA signs the certificate by using its private key. It issues the corresponding public key to all interested parties in a self-signed CA certificate. When a CA is used, scheme described above can be modified in the following manner:
Assume that the CA has issued a signed digital certificate that contains its public key. The CA self-signs this certificate by using the private key that corresponds to the public key in the certificate.
Participant 1 and Participant 2 agree to use the CA to verify their identities.
Participant 2 requests a public key certificate from the CA.
The CA verifies his/her identity, computes a hash of the content that will make up his/her certificate, signs the hash by using the private key that corresponds to the public key in the published CA certificate, creates a new certificate by concatenating the certificate content and the signed hash, and makes the new certificate publicly available.
Participant 1 retrieves the certificate, decrypts the signed hash by using the public key of the CA, computes a new hash of the certificate content, and compares the two hashes. If the hashes match, the signature is verified and Participant 1 can assume that the public key in the certificate does indeed belong to Participant 2.
Participant 1 uses Participant 2 ‘s verified public key to encrypt a message to him/her.
Participant 2 uses his/her private key to decrypt the message from Participant 1.
I discovered the difference between two (2) aspects of a typical Public Key Infrastructure (PKI). Certificate Database saves certificate requests and issued and revoked certificates and certificate requests on the certification authority (CA) whiles Certificate Store saves issued certificates and pending or rejected certificate requests on the local computer.
One important takeaway from these two articles is the importance of hashing when the certificate authority sends the public key and certificate to the organization that requests them. This hash is what allows the organization to verify the certificate authority’s identity. This is accomplished by decrypting the hashed certificate with the CA’s public key, hashing it again independently, and comparing the two hashes. If the hashes match, the organization requesting the certificate can be confident that the public key and certificate have not been tampered with.
A public key infrastructure consists of software and hardware elements that a trusted third party can use to establish the integrity and ownership of a public key. A certification authority is called by the trusted party and establishes the integrity by issuing signed binary certificates that affirm the identity of the certificate subject and bind that identity to the public key contained in the certificate. I think this is extremely important in maintaining the security of the key and makes sure that the integrity of the data is not compromised.
Reading about X.509 public key infrastructure was certainly a new thing for me. Its the standard that identifies the requirements for robust public key certificates. It also covers asymmetric cryptographic techniques and how identities are paired with cryptographic key pairs. X.509 certificates are useful for many tasks, including:
-> Authenticating clients, servers, and other devices as well as individuals and organizations.
-> Ensuring the integrity of emails, software and code, digital documents, and various data transmissions.
-> Securing data exchanges for websites and email communications using encryption. This helps to protect data both while it’s in transit and at rest.
What I gleaned from the two articles is that the public key infrastructure (PKI) system helps in eliminating spoofing attacks where an attacker could pose as one of the two communicating parties and replace their public key with its own public key. With PKI the communicating parties can trust a certification authority (CA) to have reasonably verified the identities of those intending to securely communicate. The CA issues a digitally signed certificate that is in the X.509 format and it contains information such as the name of the certificate owner, certificate validity, issuer name, serial number, etc.
Hi Nishant ,
Yes, that is accurate. By allowing a dependable third party (the CA) to confirm the identities of people interacting, PKI and X.509 aid in building trust and ensuring secure communication between parties. The CA issues X.509 certificates with vital details about the certificate owner, helping to thwart spoofing attempts. By using this approach, communicating parties can establish secure communication and confirm the validity of each other’s certificates.
My thoughtful read on these articles is that a certifying authority can employ a public key infrastructure (PKI), which consists of hardware and software components, to verify the authenticity and ownership of a public key. The certification authority, registration authority, certificate database, certificate store, and key archive server are the components of PKI. In essence, it entails the involvement of dependable third parties who use the issuance of digital certificates to confirm the identity of the parties seeking to engage in secure communication. X.509 certificates are primarily used to confirm the legitimacy of a website, a person, or a company.
Hi Mary,
Generally, I think CA is the authority of certificates and an authoritative, trusted, and impartial third-party organization with authoritative features in PKI applications, and it is also the core of the PKI system and the trust foundation of PKI, which manages the whole life cycle of public keys. If the CA stops its external service, the whole PKI system may be paralyzed. Therefore, the security and stability of CA itself are of immense importance.
PKI: system that enables secure communication over internet through use of public and private keys. It also enable the management of digital certificates.
X.509: It is a standard for encoding digital certificates that are used in PKI systems. X.509 public key certificates contain information about identity of certificate holder, their public key, digital signature of certificate issuer. They are used to verify authenticity of party’s public key. These certificates are used in many applications like SSL/TLS encryption for web traffic, email encryption and digital signatures, and secure authentication of users and devices in a network.
Both PKI and X.509 certificates are critical in ensuring secure communication. They play vital roles in securing transactions, establishing trust between parties, protecting sensitive data.
Public Key Infrastructure (PKI) is a system used to verify the identity of users and devices in the digital world. It involves the use of digital signatures from trusted parties to certify that a specific cryptographic key belongs to a particular user or device. X.509 is a standard that defines the format of these public key certificates and they are commonly used in many internet protocols such as TLS/SSL (which is used for secure browsing through HTTPS) as well as in offline applications like electronic signatures.
Public Key Infrastructure (PKI) is used to secure communications and authenticate the identity of individuals and organizations. Using public key encryption, it provides a secure method of exchanging sensitive information over public networks whose security is not verified, such as the Internet. x.509 certificate is a digital document that defines the format and structure of the digital certificate used in PKI. A digital certificate is a data file that contains information about the identity of an individual, organization, or device. X.509 certificates are used to authenticate the identity of entities involved in secure communications and transactions, such as encrypted communications based on SSL/TLS.
Public Key Infrastructure is one of the concept or areas I have been struggling to grasp how it works and it’s main purpose. However, the article shed some light to me by explaining some elements involved within the process and their descriptions.
Certification Authority
Acts as the root of trust in a public key infrastructure and provides services that authenticate the identity of individuals, computers, and other entities in a network.
Registration Authority
Is certified by a root CA to issue certificates for specific uses permitted by the root. In a Microsoft PKI, a registration authority (RA) is usually called a subordinate CA.
Certificate Database
Saves certificate requests and issued and revoked certificates and certificate requests on the CA or RA.
Certificate Store
Saves issued certificates and pending or rejected certificate requests on the local computer.
Key Archival Server
Saves encrypted private keys in the certificate database for recovery after loss.
One key takeaway is the elements that PKI (public key infrastructure) consists of the following:
1. Certification Authority – acts as the root of trust.
2. Registration Authority – certified by a root CA to issue certificates for specific uses permitted by the root.
3. Certificate Database – saves certificates requests and issued and revoked.
4. Certificate Store – saves issued certificates and pending or rejected certificate requests on the local computer.
5. Key Archival server – saves encrypted private keys in the database for recovery after loss.
I was not familiar with the Key Archival Server so it was good to know about it. Also, I had previously read about Online Certificate Status Protocol (OCSP) as online implementation of Certification Revocation List (CRL). The two other elements – Certification Database and Certificate Store in the article might be Microsoft’s way of implementing an OCSP system.
PKI is a chain of trust. An individual certificate is trusted because it can be tracked up to a trusted issuer that I can trust. I know that the certificate itself is legitimate because we can trust the x509 standard and the cryptography it is based on to prevent alteration or modification of a certificate. I do not have to trust the certificate authority that issued the certificate directly, so long as I trust one of that authority’s roots.
The analogy that I like to use for PKI is the driver’s license or passport. Anyone can put a name and a picture on a plastic card, but I won’t trust it unless I trust the issuer. I don’t have to know you or perform a background check on you to trust your name is what you say it is if i can see your government ID (certificate) because i can trust the State (Root CA) that issued it to you to confirm your identity. Similarly, Costco employees will trust a Costco card because they trust that Costco (intermediate CA) checked your ID (issued by a trusted root) before giving you the Costco card (intermediate certificate), but if you show a Sam’s Club card, they won’t accept it because they cannot trust it (different intermediate CA with no common root of trust).
Hi David,
I like your analogy. It helped me better understand the relationships between the key elements of PKI. Since Costco and Sam’s Club are registered by different institutions, we cannot confirm whether they use the same root for identity verification, the two authentications cannot communicate with each other. Thank you for sharing.
One key takeaway public key cryptography relies on a public and private key pair to encrypt and decrypt content. The keys are mathematically related, and content encrypted by using one of the keys can only be decrypted by using the other. The private key is kept secret. The public key is typically embedded in a binary certificate, and the certificate is published to a database that can be reached by all authorized users. On the other hand, an X.509 certificate contains an identity and a public key. It binds an identity such as an individual or hostname to a public key with a digital signature. The signature is either made by a trusted certificate authority (CA) or is self-signed. Some digital certificates can also be automated.
I found the chart that outlines elements of PKI to be extremely helpful.
Certification Authority:
Acts as the root of trust in a public key infrastructure and provides services that authenticate the identity of individuals, computers, and other entities in a network.
Registration Authority:
Is certified by a root CA to issue certificates for specific uses permitted by the root. In a Microsoft PKI, a registration authority (RA) is usually called a subordinate CA.
Certificate Database:
Saves certificate requests and issued and revoked certificates and certificate requests on the CA or RA.
Certificate Store:
Saves issued certificates and pending or rejected certificate requests on the local computer.
Key Archival Server:
Saves encrypted private keys in the certificate database for recovery after loss.
Understanding these elements will help you understand the hierarchy of PKI (Certification Authority/Registration Authority), in addition to how they are stored/safeguarded.
Public Key Infrastructure (PKI) provides a framework of encryption and data communications standards used to secure communications over public networks. At the heart of PKI is a trust built among clients, servers and certificate authorities (CAs). This trust is established and propagated through the generation, exchange and verification of certificates
Understanding the X.509 certificate, which is fully defined in RFC 5280, is key to making sense of those errors. Unfortunately, these certificates have a well deserved reputation of being opaque and difficult to manage. With the multitude of formats used to encode them, this reputation is rightly deserved.
An X.509 certificate is a structured, binary record. This record consists of several key and value pairs. Keys represent field names, where values may be simple types (numbers, strings) to more complex structures (lists). The encoding from the key/value pairs to the structured binary record is done using a standard known as ASN.1 (Abstract Syntax Notation, One), which is a platform-agnostic encoding format.
As mentioned in the Public Key Infrastructure, the public key infrastructure (PKI) consists of the software and hardware elements that a trusted third party can use to establish the integrity and ownership of a public key. The trusted party that signs the document that associates the key with the device is called a Certificate Authority (CA) and typically verifies that the public key has not been tampered with or corrupted during transmission by issuing a signed (encrypted) binary certificate.
The article discusses how organize a secure method of information exchange between individuals. For this purpose, asymmetric-key cryptography is used. The key pair consists of one public and one private key to encrypt and decrypt content. Both keys are mathematically related. Individuals involved in the process of communication should distribute the public key but must keep the privet key secret. Message encrypted by using one of the keys can be decrypted by using the other according to the following scheme. Participant 1 and Participant 2 have their own key pairs. They have kept their private keys securely to themselves and have sent their public keys directly to each other. Participant 1 uses Participant 2’ s public key to encrypt the message and sends it to him/her. Participant 2 uses his/her private key to decrypt the message. However at least one obvious concern Participants must have about the public key they used to encrypt the message. That is, they cannot know with certainty that the key Participant 1 used for encryption actually belonged to Participant 2. It is possible that another party monitored the communication channel between Participants and substituted a different key. The public key infrastructure concept has evolved to help address this problem and others. A public key infrastructure (PKI) consists of software and hardware elements that a trusted third party can use to establish the integrity and ownership of a public key. The trusted party, called a certification authority (CA), typically accomplishes this by issuing signed (encrypted) binary certificates that affirm the identity of the certificate subject and bind that identity to the public key contained in the certificate. The CA signs the certificate by using its private key. It issues the corresponding public key to all interested parties in a self-signed CA certificate. When a CA is used, scheme described above can be modified in the following manner:
Assume that the CA has issued a signed digital certificate that contains its public key. The CA self-signs this certificate by using the private key that corresponds to the public key in the certificate.
Participant 1 and Participant 2 agree to use the CA to verify their identities.
Participant 2 requests a public key certificate from the CA.
The CA verifies his/her identity, computes a hash of the content that will make up his/her certificate, signs the hash by using the private key that corresponds to the public key in the published CA certificate, creates a new certificate by concatenating the certificate content and the signed hash, and makes the new certificate publicly available.
Participant 1 retrieves the certificate, decrypts the signed hash by using the public key of the CA, computes a new hash of the certificate content, and compares the two hashes. If the hashes match, the signature is verified and Participant 1 can assume that the public key in the certificate does indeed belong to Participant 2.
Participant 1 uses Participant 2 ‘s verified public key to encrypt a message to him/her.
Participant 2 uses his/her private key to decrypt the message from Participant 1.
I discovered the difference between two (2) aspects of a typical Public Key Infrastructure (PKI). Certificate Database saves certificate requests and issued and revoked certificates and certificate requests on the certification authority (CA) whiles Certificate Store saves issued certificates and pending or rejected certificate requests on the local computer.
One important takeaway from these two articles is the importance of hashing when the certificate authority sends the public key and certificate to the organization that requests them. This hash is what allows the organization to verify the certificate authority’s identity. This is accomplished by decrypting the hashed certificate with the CA’s public key, hashing it again independently, and comparing the two hashes. If the hashes match, the organization requesting the certificate can be confident that the public key and certificate have not been tampered with.