Cisco Cisco Email Security Appliance C670 Libro bianco

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Organization A sending a message to Organization B:

1. Alice (Organization A) uses an email client to send an unsigned and 

unencrypted message to Erin (Organization B).

2. Cisco Email Security Appliance in Organization A signs and encrypts 

the messages and sends it to Organization B.

3. The email client in the Organization B decrypts and verifies the 

message and displays it to Erin.

Organization B sending a message to Organization A:

1. Erin (Organization B) uses the email client to sign and encrypt a 

message and sends it to Alice (Organization A).

2. Cisco Email Security Appliance in Organization A decrypts and 

verifies the message.

3. Alice receives the unencrypted and unsigned message.

Cisco Email Security S/MIME Certificate Installation Requirements

Note:

 For production environments, it is highly recommended organizations buy 

an S/MIME certificate from a trusted and established certificate authority that 

your organization would like to use for business purposes.

Creating a certificate for use with S/MIME signing on Cisco Email 

Security as noted below is not recommended for production use, but 

can provide good exposure in test environments.

When you create an S/MIME certificate for message signing, it must 

meet the requirements described in 

: Secure/Multipurpose 

Internet Mail Extensions (S/MIME) Version 3.2 - Certificate Handling.

For this process, the use of an external application is required in order to 

generate the certificate. The X Certificate and Key Management (XCA) 

is an application that manages asymmetric keys, such as Rivest-Shamir-

Addleman (RSA) or Digital Signature Algorithm (DSA), and is intended 

to be a small certificate authority (CA) for the creation and signing of 

certificates. It uses the Open Secure Sockets Layer (OpenSSL) library 

for the cryptographic operations.

Note:

 The XCA is a third-party application that is not supported by Cisco. The use 

of this application is provided only for illustration and ease of administration for S/

MIME administration, testing, and configuration. For full details and instructions on 

XCA, refer to the 

You can download the XCA application at either of these locations:

Macintosh Operating Systems (OSX): 

.

Microsoft Windows Systems: 

Create a Certificate

Complete these steps in order to create an S/MIME certificate:

Use the XCA application in order to create a new XCA database or open 

a current XCA database, if one already exists.

a. From the menu bar, navigate to 

File > New Database > <DB name a. 

of your choice>:

Cisco Email Security How-To Guide

How-To Secure Communications

Cisco Public