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On Thursday 19 Jan 2012 23:20:44 Dale wrote: |
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> Chris Walters wrote: |
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> I'm starting to see this now. When I sign a message, it is public but |
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> people are assured that it came from me. Sort of like having a check |
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> with a picture ID that matches. :/ |
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Better than that. |
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Readers (all that have access to this list) can a)see that you have signed it |
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and b)rest assured that no one has tampered with its content since you signed. |
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If anyone intercepted the message mid-air and changed its content, your |
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signature would show as bad in the recipients mail client (assuming they have |
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a GnuPG/PGP compatible client). |
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BTW, your signature is not showing in Kmail ... are you using inline or |
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opengpg/smime format? |
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> > You could then encrypt a message to me, and you could add yourself |
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> > to the recipient list so you could read it. Then, when I received |
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> > the message, I would be prompted for my secret key's passphrase - |
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> > this would allow decryption of the message. Providing that I |
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> > replied to you and chose the "encrypt" option, the entire message, |
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> > including any quotes would be encrypted. |
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> > |
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> > Hope this helps, Chris |
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> So, this is why when I want to sign a message it asks me for the |
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> password. I thought it was trying to do something wrong. Made me |
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> scratch my head. |
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To avoid an easy misunderstanding about what the "password" does: |
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You are asked for a passphrase not because Chris used that passphrase to |
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encrypt the message he sent you with (that would have been symmetric |
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encryption and both of you would need to know in advance the secret |
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passphrase). Instead, you are asked for a passphrase to decrypt your own |
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private gpg key which is stored in encrypted format on your hard drive for |
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security purposes. The private key once decrypted and loaded in memory will |
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be used by your openpgp application to decrypt the message sent by Chris. |
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This is asymmetric encryption: a sender can use your public key and their |
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private key to encrypt a message to you, which only you can decrypt with your |
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private key and the sender's public key. Look at the picture on the right in |
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this page: |
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http://en.wikipedia.org/wiki/Public-key_cryptography |
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HTH |
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-- |
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Regards, |
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Mick |
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