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I'm reading about a Public key certificate:

In cryptography, a public key certificate, also known as a digital certificate or identity certificate, is an electronic document used to prove the ownership of a public key.

From the wiki for an Electronic document:

An electronic document is any electronic media content (other than computer programs or system files) that are intended to be used in either an electronic form or as printed output.

In this case, if I'm curious if a public key certificate is a plain-text file or a binary file does the term "electronic document" tell me any information?

Specifically, would a data file with the extension .cer and a plain-text file with the extension .p12 both be considered "electronic documents"?

  • Yes; they're both composed of electrons and not paper :) – John Wu Mar 17 '17 at 0:47
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In this case, I would recommend not overthinking it.

The primary reason why it matters that it is an "electronic" document is that the document can be readily copied by electronic means. In public key encryption, you typically transmit the public key over an electronic medium like the internet. This means the document can be trivially copied and there is no concept of an "original" document being any more meaningful than a copy of the original.

The fact that it's electronic is not essential, but it is helpful for avoiding some potential mishaps if you think about things the wrong way. For example, if I am crossing a border and want to prove my identity to a border patrol agent, I would show them my passport. They'd look at it, verify it, and then hand it back to me. In the case of an electronic document, because the content is just bytes, the normal pattern to prove your identity is that you give the officer a copy of your electronic document, and then they keep the copy. Most of the time they dispose of it because they have no further use for it, but in theory they could keep it forever, and their copy is as good as my original. Accordingly, the security proofs regarding electronic identity documents tend to take a different tack than security proofs regarding physical documents.

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