diff --git a/keystoremanager/keystoremanager.go b/keystoremanager/keystoremanager.go
index 09f336de0b..6b61f1c009 100644
--- a/keystoremanager/keystoremanager.go
+++ b/keystoremanager/keystoremanager.go
@@ -24,7 +24,8 @@ type KeyStoreManager struct {
 }
 
 const (
-	trustDir       = "trusted_certificates"
+	trustDir = "trusted_certificates"
+	// PrivDir is the name of the private directory
 	PrivDir        = "private"
 	rsaRootKeySize = 4096 // Used for new root keys
 )
diff --git a/tuf/data/keys.go b/tuf/data/keys.go
index 22a1fb786c..63582db054 100644
--- a/tuf/data/keys.go
+++ b/tuf/data/keys.go
@@ -486,18 +486,22 @@ func (k UnknownPrivateKey) Sign(rand io.Reader, msg []byte, opts crypto.SignerOp
 	return nil, errors.New("Unknown key type, cannot sign.")
 }
 
+// SignatureAlgorithm returns the SigAlgorithm for a ECDSAPrivateKey
 func (k ECDSAPrivateKey) SignatureAlgorithm() SigAlgorithm {
 	return ECDSASignature
 }
 
+// SignatureAlgorithm returns the SigAlgorithm for a RSAPrivateKey
 func (k RSAPrivateKey) SignatureAlgorithm() SigAlgorithm {
 	return RSAPSSSignature
 }
 
+// SignatureAlgorithm returns the SigAlgorithm for a ED25519PrivateKey
 func (k ED25519PrivateKey) SignatureAlgorithm() SigAlgorithm {
 	return EDDSASignature
 }
 
+// SignatureAlgorithm returns the SigAlgorithm for an UnknownPrivateKey
 func (k UnknownPrivateKey) SignatureAlgorithm() SigAlgorithm {
 	return ""
 }