Is the signature field a public key?

Question

Electronic digital signature

Good day.

I want to understand the work of one program.

I have JSON like this:

{
  "some_field": "{\"name\": null, \"uuid\": null, \"offline\": false}",
  "signature": "ACmDAGIw9Zu7i73HUqnD8zuTuNbknSTL2nzxdF0X3A+1527zBePP+BVbIMyZ+5D0IXSbo5eP2rO80kqqqRPCsOafjFgHMicXPJASzIWSecsSqDiroBbMgtVQo2Xc1oRaq/pA9SSbTpcHLpDOBruHazurgsCgNzn16EP8xNVuV6OXhYhB6SsCURqW2c/THAH5Q/XeGVX7jH87o02PrhlZLIMLuyD3WmJQuIPZVKvlcZFxIEXJ5Qh1IPVjRHf7/mWI16lsbhpHVTmuPR3JJpZTwKAjucq+fOE0stmKjzIYgMc3jnjmVB8MtLhWxfhJeLJE0Qijvk/+3eb8Hfai7ji9NA=="
}

This JSON, or the "signature" field in it, is validated by a file called "public_key", but judging by the content, it contains several blocks, denoted by certificates:

-----BEGIN CERTIFICATE-----
MIIGpDCCBIygAwIBAgICEAAwDQYJKoZIhvcNAQELBQAwdDELMAkGA1UEBhMCUlUx
DzANBgNVBAcMBk1vc2NvdzEjMCEGA1UECgwaUGFyYWxsZWxzIElQIEhvbGRpbmdz
IEdtYkgxEDAOBgNVBAsMB0Rlc2t0b3AxHTAbBgNVBAMMFFBhcmFsbGVscyBEZXNr
dG9wIENBMB4XDTE4MTIyNDA5MDM1N1oXDTI4MTEwNjA5MDM1N1owdzELMAkGA1UE
BhMCUlUxDzANBgNVBAcTBk1vc2NvdzElMCMGA1UEChMcUGFyYWxsZWxzIEludGVy
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eKua/1Ngt9U3Y6fPwP6gVaQglZBcPgs5+4a+hd/8gPZ+XbVXsK68j9eUMuhMoFdK
caNejnQt3Cvsnp7ohSoRY3rKdfG0Idy/4HJCiCCOnDDpPXvqQqAo0cwEhbSjI66Y
zdtEkCFpWz23rGElQMxIs6ojwK/gu5+sJpE+l7QpXfCIhryqGqRHpdkSDp7Pc1Jr
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puKPoOE9EMI74XzKw5FsVhVUp8Wem8Ir7eP6GZ7hP21J7C9tPkiYjJqX6jJvvLE6
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YScGlH58rXXjAZv+kHNTsJ+zLX//KpzT
-----END CERTIFICATE-----
-----BEGIN CERTIFICATE-----
MIIH9TCCBd2gAwIBAgICEAMwDQYJKoZIhvcNAQELBQAwdDELMAkGA1UEBhMCUlUx
DzANBgNVBAcMBk1vd2NvdzEjMCEGA1UECgwaUGFyYWxsZWxzIElQIEhvbGRpbmdz
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BhMCUlUxDzANBgNVBAcMBk1vc2NvdzEjMCEGA1UECgwaUGFyYWxsZWxzIElQIEhv
bGRpbmdzIEdtYkgxEDAOBgNVBAsMB0Rlc2t0b3AxHTAbBgNVBAMMFFBhcmFsbGVs
cyBEZXNrdG9wIENBMIICIjANBgkqhkiG9w0BAQEFAAOCAg8AMIICCgKCAgEA2r6P
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eo6QhWmNlc3k/k63MhxRNe55cq64VyskFA==
-----END CERTIFICATE-----

I have not come across digital signature and certificates before.

I googled and generated a certificate and a private key using openssl as a test. Then, using a different tutorial, I generated public and private keys. None of the tutorials I read mentioned "signature".

Actually, what is the "signature" field in JSON in this context and how to interact with it?
Those. Can I somehow use one of the certificates from the "public_key" file and the value from the "signature" field to verify the value of the "some_field" field? If so, how?

Answer 1

There are different types of information security.
There is an electronic signature. There is encryption. There is a combination of these things - it is usually used to protect e-mail.
An electronic signature does not encrypt anything. It calculates the signature of the text and places this signature in the transmitted message. By checking this signature, you can verify that the text is intact (that is, that it was not distorted during transmission).
Encryption changes the text of the document, turning it into an unreadable canoe.
The electronic signature of the ciphertext allows you to make sure that the text will be successfully decrypted.