When attempting to sign a file with PGP Command Line, you receive the following error:
1054:too many matches for signing key
This can occur when the specified key being used for signing has a UserID that matches or is similar to the UserID of multiple other keys. PGP Command Line returns the error code as it cannot determine which key to use for signing.
PGP Command Line allows you to specify the Key ID when signing instead of using the key's User ID. Specifying the Key ID will ensure that only 1 key is matched.
To specify the Key ID
Type the Key ID in the after --signer following command when signing a file: