Whoever receives an e-mail nowadays cannot rely on the fact that it actually originates from the specified sender. Nor can the recipient be certain that a message which has been received is unchanged and complete. E-mail sender data are increasingly being falsified by worms and spams.

This is why we at Bischof+Klein have decided to provide each e-mail which leaves the company with a digital signature, therefore making information exchange secure and trustworthy. The message is "electronically sealed" by this signature. As the recipient, you can now reliably determine whether

• the message has been changed on its way to you (integrity of the transmitted data)
• the message actually originates from Bischof+Klein (authenticity of the data source)

To check the validity of mails signed by us, you have to install the following certificates, which can be downloaded from Deutsche Telekom's T-Telesec Trustcenter:

Shared Business CA Certificate

Deutsche Telekom Root CA 2 Certificate

MailPass CA Certificate

Deutsche Telekom Root CA 1 Certificate

In addition, we offer confidential communication with encryption using S/MIME and PGP. The digital signature below our e-mails simultaneously provides you with our public key. This enables you to send us an encrypted message.

If you also have a public key yourself, please make this available to us. We are then able to send to send you encrypted e-mails. If you already use certificates and these are accessible via a public LDAP server, we would be grateful if you would send us this information via our contact form, stating the key word "LDAP server information".

More information on the following topics:

• Certificates
• Trustcenter
• Encryption
• Digital signature
• Legal bases

can be found on the Deutsche Telekom T-Telesec Trustcenter web site.