Cisco Cisco Email Security Appliance C160 Mode D'Emploi
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User Guide for AsyncOS 10.0 for Cisco Email Security Appliances
Chapter 20 S/MIME Security Services
Signing, Encrypting, or Signing and Encrypting Outgoing Messages using S/MIME
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).
(Organization B).
2.
Email Security appliance in the Organization A signs and encrypts the messages and sends it to
Organization B.
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).
(Organization A).
2.
Email Security appliance in the Organization A decrypts and verifies the message.
3.
Alice receives an unencrypted and unsigned message.
Signing, Encrypting, or Signing and Encrypting Outgoing
Messages using S/MIME
Messages using S/MIME
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Note
You can use Email Security appliance to sign, encrypt, and sign and encrypt outgoing and incoming
messages.
messages.
S/MIME Signing and Encryption Workflow in Email Security Appliance
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S/MIME Signing Workflow
The following process describes how Email Security appliance performs S/MIME signing.
1.
Apply a hash algorithm to the message to create a message digest.
2.
Encrypt the message digest using private key of the appliance’s S/MIME certificate.