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| pgpfan:pgpauth [2025/10/11 16:47] – [The PGP OCFB-MDC Encryption Mode] Forgot footer again. b.walzer | pgpfan:pgpauth [2025/11/01 11:57] (current) – [The Why of PGP Authentication] Typo b.walzer |
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| ======The Why of PGP Authentication====== | ======The Why of PGP Authentication====== |
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| There seems to be an ongoing misunderstanding of how PGP actually does authentication. That ends up being important in various discussions. Let's dig into perhaps the more interesting question of //why// PGP does the things it does and pick up the //how// along the way. | There seems to be an ongoing misunderstanding of how PGP actually does authentication. That ends up being important in various discussions. Let's dig into perhaps the more interesting question of //why// PGP does the things it does and pick up the //how// along the way. |
| Authentication in a PGP context is a mechanism that makes it possible for the recipient of a file/message to verify that the file/message was certified by a particular entity/person. It also insures that the file/message was not tampered with after that certification. The most common convention is that the certification is a declaration that the certifier created a particular file/message. More generally, such a certification means that the certifier is taking responsibility for the file/message in some way. | Authentication in a PGP context is a mechanism that makes it possible for the recipient of a file/message to verify that the file/message was certified by a particular entity/person. It also insures that the file/message was not tampered with after that certification. The most common convention is that the certification is a declaration that the certifier created a particular file/message. More generally, such a certification means that the certifier is taking responsibility for the file/message in some way. |
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| Cryptographic signatures will be important here so we should briefly define the term. The generation of a [[wp>Digital_signature|cryptographic signature]] requires knowledge of a secret value normally only known by single entity/person. There is a public value that corresponds to the secret value. Anyone can take that public value, the signed data and the cryptographic signature and verify that the signer had access to the secret value when they created the cryptographic signature. Cryptographic signatures often form the root of authentication schemes. | Cryptographic signatures will be important here so we should briefly define the term. The generation of a [[wp>Digital_signature|cryptographic signature]] requires knowledge of a secret value normally only known by a single entity/person. There is a public value that corresponds to the secret value. Anyone can take that public value, the signed data and the cryptographic signature and verify that the signer had access to the secret value when they created the cryptographic signature. Cryptographic signatures often form the root of authentication schemes. |
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| =====PGP Authentication Doesn't Work This Way===== | =====PGP Authentication Doesn't Work This Way===== |
