diff --git a/tar/storage/entry.go b/tar/storage/entry.go
index a9575db..77dc320 100644
--- a/tar/storage/entry.go
+++ b/tar/storage/entry.go
@@ -24,10 +24,15 @@ const (
 
 // Entry is a the structure for packing and unpacking the information read from
 // the Tar archive.
+//
+// FileType Payload checksum is using `hash/crc64` for basic file integrity,
+// _not_ for cryptography.
+// From http://www.backplane.com/matt/crc64.html, CRC32 has almost 40,000
+// collisions in a sample of 18.2 million, CRC64 had none.
 type Entry struct {
 	Type     Type   `json:"type"`
 	Name     string `json:"name",omitempty`
 	Size     int64  `json:"size",omitempty`
-	Payload  []byte `json:"payload"` // SegmentType store payload here; FileType store checksum here;
+	Payload  []byte `json:"payload"` // SegmentType store payload here; FileType store crc64 checksum here;
 	Position int    `json:"position"`
 }