User can load his/her personal digital certificate which he/she can use to sign the messages so recipients can verify that the message was sent really by the user. The certificate can be obtained from certification authority like Thawte or VeriSign.
User can load certificate either from file or manually paste the certificate to the appropriate dialog. The certificate has to be in the following format:
-----BEGIN CERTIFICATE-----
public certificate according to the X.509 standard encoded in Base64 Enconding
-----END CERTIFICATE-----
-----BEGIN RSA PRIVATE KEY-----
private certificate according to the X.509 standard encoded in Base64 Enconding
-----END RSA PRIVATE KEY-----
Private certificate password option has to be filled by the password which user filled during the acquire process of certificate from Certification Authority.
Default Encrypt and Default Sign options affect options Encrypt and Sign in the New Message dialog.
Certificate Info dialog is generated automatically according to the filled certificate.
After loading the certificate user can sign composed messages by checking the Sign checkbox in the New Message dialog and special hash generated from his public and private keys and content of message is attached to the message and recipient can verify whether the hash is correct by the Certification Authority which signed the personal certificate used by user.