gnupg gives me the error "Invalid public key algorithm" when I try to use an old key

Question

When I try to decrypt an old file, gpg2 gives me this error:

gpg: public key decryption failed: Invalid public key algorithm
gpg: decryption failed: No secret key

gpg1 gives me this error:

gpg: Ohhhh jeeee: no decrypt() for 17
secmem usage: 1664/2432 bytes in 5/8 blocks of pool 2432/32768
Abort trap: 6

Answer 1

You get this message when you've imported an old secret key but not the corresponding public key. Go back and import the public key as well.