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I have already been able to manage to encrypt/decrypt files using one Public Key. Now I'd like to encrypt files with PGP for multiple receipients. How can I achieve this?

stromflut
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2 Answers2

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I assume you are doing something like this:

PgpEncryptedDataGenerator encryptedDataGenerator = // ...
encryptedDataGenerator.AddMethod(publicKey);
encryptedDataGenerator.Open(outputStream, buffer);

Just add the public keys for the other recipients using the AddMethod()-method multiple times:

PgpEncryptedDataGenerator encryptedDataGenerator = // ...
foreach(PgpPublicKey publicKey in publicKeys){
  encryptedDataGenerator.AddMethod(publicKey);
}
encryptedDataGenerator.Open(outputStream, buffer);
Rasmus Faber
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    This seems to work for the encryption, but there is another problem in decrypting the encrypted files afterwards. If I decrypt the file with the secret Key of the First-added PublicKey, I get the Original File back. But if I use the secret key of the secondly-Added Public Key, I get a "exception decrypting secret key"-Error. It's allways the second key which generates some Problems - even if I switch the Position of these two Keys... – stromflut Mar 05 '12 at 14:49
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I'm in a similar situation. I've resorted to making a random session key myself, which is encrypted several times; one for each target. It's a little messy to get everything working though. I'm not sure if it's really supported by OpenPGP straight out of the box (even though the function names seem to suggest it)

lulzmachine
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