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7. SSL/TLS function
7-1.
Overview
Necessity of SSL/TLS support
Encrypted communication is necessary to prevent third parties from eavesdropping on, altering, or
spoofing the communication data flowing over the network. The SSL/TLS protocol has become the
standard for encrypted communication infrastructure.
The http protocol is used to send and receive web data and XML data, and https is the SSL/TLS-
compatible version of it. If https is used for communication between the host and the printer, the
printer must also support SSL/TLS.
Overview of SSL/TLS support
A digitally signed certificate (hereafter referred to as a signed certificate) is required for SSL/TLS
encrypted communication. The server stores the signed certificate, and the client side must confirm
or approve the certificate as trustworthy to enable SSL/TLS encrypted communication.
There are two types of signing certificates: those signed by a public certification authority (CA) and
self-signed certificates signed by the private CA.
In the case of self-signed certificates, the client side must certify that the certificate is trustworthy so
that it can communicate without warning. For this purpose, this board has a function to export a file
that contains the unique information for certification.
This board also allows importing a certificate signed by a public CA for more secure communication.
Differences in procedures for preparing signed certificates between this board and a normal server
For SSL/TLS communication, you will need a signed certificate file and a private key file. The general
procedure for preparing these on a normal server is as follows.
1. The applicant requesting the certificate generates a private key.
2. Applicant creates a certificate signing request (CSR) by entering the applicant's identification
information and adding a signature with the applicant's private key.
3. The applicant submits the CSR to either a self-certification authority prepared by the applicant or
an external public CA.
4. The signing authority generates a certificate with its own private key signature attached to the
CSR and returns it to the applicant. (Depending on the submitted certification authority, the
certification becomes either a self-signed certificate or a public CA signed certificate).
5. The applicant stores and places the signed certificate file and his private key file.
This board has an internal private key and self-certification authority, and if you want to use a self-
signed certificate, you only need to enter the identification information in step 2 above. (For the
detailed procedure, refer to 7-3-1 Creating and exporting a self-signed certificate.