Besides protecting communications certificates also can protect content and verify the identity of the
content.
Author.
When you receive a message with confidential content, you need to be confident about two things that
the message was not modified in transit and the identity of the author is verifiable.
You can also use certificates to protect and verify content and to verify the identity of an author.
It is common for a user to sign a document digitally.
No digital signatures when a person digitally signs a document in an application such as an email or
a microsoft Word document.
Sure, she confirms that the document is authentic.
In this context, authentic means that it is known who created and signed a document and that no one
has altered the document since a public key infrastructure or PGI cannot achieve this level of security
compared to the web server from the previous topic.
A user also can have a certificate for the public and private key pair.
This certificate is used in the process of digital signing when an author digitally signs a document
or a message.
The operating system on his or her computer creates a message.
Cryptographic digit digest that ranges from 128 bit to 256 bit number.
It is generated by running the entire message through a hash algorithm.
This number then is encrypted by using the author's private key and it is added to the amount of the
document or message.
When the document or message reaches the recipient.
It will go through the same hash algorithm as when the author digitally signed it.
Also, the recipient uses the author's public key to decrypt the digest that is added to the message
after it is decrypted.
It is compared to the digest the recipient has generated and if they are the same, the document or
the message was not altered urine.
Transport also if the recipient can decrypt their budget by using the authorities public key.
This meant the digest was encrypted by using the author as private key, and that confirms the author's
identity as the end.
The recipient also verifies the certificate that proved the authors identity.
During this check, the recipient also verifies the validity period serial subject name and certificate
chain trust.
Nelson wrote about implementing, implement and digital signatures.
To implement digital signatures.
An internal communications unit to issue certificates based on the user template.
You also issue certificates to all users.
Who use digital signatures.
Who can issue the certificate without any user intervention?
If you use auto enrolment also users must use an application that supports content signing.
For example, you can use digital ID digital signatures by default in Windows.
Microsoft Word and Microsoft Outlook.
Digital signatures are ready to use after the application issues and configure the certificate after
you sent digitally signed content outside of your organisation.
You might experience you trust issues in this scenario.
A recipient is not in the same EDS domain as the author, so it does not trust the CAA that issued the
certificate for the digital signature.
Although this type of digital signature will still be valid from a content production perspective,
an application will probably generate a warning on the recipient side.
If you need to send digitally signed content to recipients outside of your organisation, it is recommended
that you buy a certificate from a public global trusted see.
Next up, we'll have a demonstration where we'll see how to sign a document digitally.