Using Certificates with HP-UX IPSec

OverviewOverview

You must use security certificates if you are using digital signatures (RSA signatures) for IKE authentication. HP-UX IPSec uses the certificates to obtain cryptography keys for digital signatures and to verify the digital signatures. If you are not using digital signatures for IKE authentication, you can skip this chapter.

Security Certificates and Public Key Cryptography

Security certificates are used for public key cryptography, also referred to as asymmetric key cryptography. Public key cryptography uses a pair of related, but different keys. One key, the private key, is associated with a specific system or entity and is kept secret; the other key is the public key and can be distributed freely. The public and private keys are mathematically related so that data encrypted with the public key can only be decrypted with the private key.

Public Key Distribution

With asymmetric key cryptography, the public key can be freely distributed over a non-secure communication channel.

However, there must be some assurance that a particular public key is the actual public key of the entity with which you want to communicate. This is usually done by distributing public keys in the form of public-key certificates, commonly referred to as security certificates.

Security Certificates

A security certificate associates (or binds) a public key with a particular person, device, or other entity. The certificate is issued by an entity, in whom users have put their trust, called a certificate authority (CA) that guarantees or confirms the identity of the holder (person, device, or other entity) of the corresponding private key. The CA digitally signs the certificate with the CA’s private key, so the certificate can be verified using the CA’s public key.

The format for security certificates (public-key certificates) is defined by the International Organization for Standardization (ISO) X.509 standard, Version 3.

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