X.509
Sign in to saveIn cryptography, X.509 is an International Telecommunication Union (ITU) standard defining the format of public key certificates. X.509 certificates are used in many Internet protocols, including TLS/SSL, which is the basis for HTTPS, the secure protocol for browsing the web. They are also used in offline applications, like electronic signatures.
Key facts
- Technology standard.title
- X.509
- Technology standard.long_name
- Information technology - Open Systems Interconnection - The Directory: Public-key and attribute certificate frameworks
- Technology standard.status
- In force (Recommendation)
- Technology standard.version
- 9.2
- Technology standard.organization
- ITU-T
- Technology standard.committee
- ITU-T Study Group 17
- Technology standard.base_standards
- ASN.1
- Technology standard.related_standards
- ISO/IEC 9594-8:2020, X.500
- Technology standard.domain
- Cryptography
- Technology standard.series
- X
- Technology standard.first_published
- 1.0 at
- File format.name
- X.509 certificate
- File format.mime
- application/pkix-cert
- File format.uniform type
- public.x509-certificate
via Wikipedia infobox
Article
26 sectionsContents
- History and usage
- Certificates
- Structure of a certificate
- Extensions informing a specific usage of a certificate
- Extended Validation certificates
- Certificate filename extensions
- Certificate chains and cross-certification
- Examples
- Example 1: Cross-certification at root Certification Authority (CA) level between two PKIs
- Example 2: CA certificate renewal
- Sample X.509 certificates
- End-entity certificate
- Intermediate certificate
- Root certificate
- Security
- Architectural weaknesses
- Problems with certification authorities
- Implementation issues
- Cryptographic weaknesses
- Mitigations for cryptographic weaknesses
- PKI standards for X.509
- PKIX Working Group
- Major protocols and standards using X.509 certificates
- See also
- References
- External links
In cryptography, X.509 is an International Telecommunication Union (ITU) standard defining the format of public key certificates. X.509 certificates are used in many Internet protocols, including TLS/SSL, which is the basis for HTTPS, the secure protocol for browsing the web. They are also used in offline applications, like electronic signatures.
An X.509 certificate binds an identity to a public key using a digital signature. A certificate contains an identity (a hostname, or an organization, or an individual) and a public key (RSA, DSA, ECDSA, ed25519, etc.), and is either signed by a certificate authority or is self-signed. When a certificate is signed by a trusted certificate authority, or validated by other means, someone holding that certificate can use the public key it contains to establish secure communications with another party, or validate documents digitally signed by the corresponding private key.