feat!: add deprecating message for the encrypted package (#521)

* feat!: add deprecating message for the encrypted package

Signed-off-by: Radoslav Dimitrov <dimitrovr@vmware.com>

* chore: switch to using go-sslib/encrypted package

Signed-off-by: Radoslav Dimitrov <dimitrovr@vmware.com>

---------

Signed-off-by: Radoslav Dimitrov <dimitrovr@vmware.com>
diff --git a/encrypted/encrypted.go b/encrypted/encrypted.go
index 037a718..b884d61 100644
--- a/encrypted/encrypted.go
+++ b/encrypted/encrypted.go
@@ -3,6 +3,10 @@
 //
 // It uses scrypt derive a key from the passphrase and the NaCl secret box
 // cipher for authenticated encryption.
+//
+// Deprecated: The encrypted package from go-tuf is already moved to
+// https://github.com/secure-systems-lab/go-securesystemslib and will be deprecated here.
+// Use github.com/secure-systems-lab/go-securesystemslib/encrypted instead.
 package encrypted
 
 import (
diff --git a/local_store.go b/local_store.go
index fee03f3..b59721e 100644
--- a/local_store.go
+++ b/local_store.go
@@ -12,8 +12,8 @@
 	"path/filepath"
 	"strings"
 
+	"github.com/secure-systems-lab/go-securesystemslib/encrypted"
 	"github.com/theupdateframework/go-tuf/data"
-	"github.com/theupdateframework/go-tuf/encrypted"
 	"github.com/theupdateframework/go-tuf/internal/fsutil"
 	"github.com/theupdateframework/go-tuf/internal/sets"
 	"github.com/theupdateframework/go-tuf/pkg/keys"
diff --git a/repo_test.go b/repo_test.go
index 4d7d73f..01ae341 100644
--- a/repo_test.go
+++ b/repo_test.go
@@ -20,8 +20,8 @@
 	"time"
 
 	"github.com/secure-systems-lab/go-securesystemslib/cjson"
+	"github.com/secure-systems-lab/go-securesystemslib/encrypted"
 	"github.com/theupdateframework/go-tuf/data"
-	"github.com/theupdateframework/go-tuf/encrypted"
 	"github.com/theupdateframework/go-tuf/internal/sets"
 	"github.com/theupdateframework/go-tuf/pkg/keys"
 	"github.com/theupdateframework/go-tuf/pkg/targets"