Can't PGP decrypt message

Question

Hello,
I'm having problems with decrypting messages from a friend. I have his public key imported and signed as trustworthy, but I could't decrypt messages he encrypts with my key.
Enigmail says: "Error: signature verification failed", and by trying manually through gpg i get the following:
You need a passphrase to unlock the secret key for
user: "Luther Throl <[email protected]>"
4096-bit RSA key, ID 4EDC5AAA, created 2014-01-23 (main key ID C874D86F)
gpg: problem with the agent: Line passed to IPC too long
gpg: encrypted with 4096-bit RSA key, ID 4EDC5AAA, created 2014-01-23
"Luther Throl <[email protected]>"
gpg: public key decryption failed: Operation cancelled
gpg: decryption failed: No secret key
Last edited by luther7hrol (2014-01-26 22:48:00)

Answer 1

luther7hrol wrote:
Hello,
I'm having problems with decrypting messages from a friend. I have his public key imported and signed as trustworthy, but I could't decrypt messages he encrypts with my key.
The way you've worded this suggests you're not clear on how public/private keypair systems work. Having your friend's public key is irrelevant to whether or not your friend can send you encrypted messages. To send you encrypted messages, there is only one requirement: that you have your private key kept secret on your destination machine, and your friend has access to your public key from their machine.
luther7hrol wrote:
Enigmail says: "Error: signature verification failed", and by trying manually through gpg i get the following:
You need a passphrase to unlock the secret key for
user: "Luther Throl <[email protected]>"
4096-bit RSA key, ID 4EDC5AAA, created 2014-01-23 (main key ID C874D86F)
gpg: problem with the agent: Line passed to IPC too long
gpg: encrypted with 4096-bit RSA key, ID 4EDC5AAA, created 2014-01-23
"Luther Throl <[email protected]>"
gpg: public key decryption failed: Operation cancelled
gpg: decryption failed: No secret key
This doesn't say a lot without knowledge of what commands you used to generate the key and decrypt the message.
When I was learning to use GPG/PGP, I set up some dummy accounts on my machine for fake users called Alice, Bob and Eve. Then I did exercises like setting up key pairs for Alice and Bob, and have Bob create a signed message encrypted for Alice, and then see what information Eve can discover when "she" intercepts the message. You might wish to consider doing similar exercises.