diff --git a/src/main.go b/src/main.go
index f4fc107..7e6730d 100644
--- a/src/main.go
+++ b/src/main.go
@@ -14,15 +14,6 @@ import (
 
 const Version = "1.3.0"
 
-// Config and SSH types are now in separate packages
-
-// SSH connection methods are now in ssh.go
-
-// YAML processing is now handled by the config package
-
-// SSH helper functions are now in ssh.go
-
-// processDevice handles backup processing for a single device
 func processDevice(hostname string, deviceConfig Device, commands []string, excludePatterns []string, password, keyFile string, port int, outputDir string) bool {
 	// Create backup instance
 	backup := NewRouterBackup(hostname, deviceConfig.Address, deviceConfig.User, password, keyFile, port)
@@ -82,18 +73,25 @@ func main() {
 			}
 
 			// Check authentication setup
-			if password == "" && keyFile == "" {
-				if os.Getenv("SSH_AUTH_SOCK") != "" {
-					fmt.Println("Using SSH agent for authentication")
-				} else {
-					keyFile = findDefaultSSHKey()
-					if keyFile == "" {
-						log.Fatal("No SSH key found and no password provided")
-					} else {
-						fmt.Printf("Using SSH key: %s\n", keyFile)
-					}
+			hasAuth := 0
+			if os.Getenv("SSH_AUTH_SOCK") != "" {
+				fmt.Println("Using SSH agent for authentication")
+				hasAuth++
+			}
+			if keyFile == "" {
+				keyFile = findDefaultSSHKey()
+				if keyFile != "" {
+					fmt.Printf("Using SSH key: %s\n", keyFile)
+					hasAuth++
 				}
 			}
+			if password != "" {
+				fmt.Println("Using --password for authentication")
+				hasAuth++
+			}
+			if hasAuth == 0 {
+				log.Fatal("No authentication mechanisms found.")
+			}
 
 			// Process devices
 			if len(cfg.Devices) == 0 {