diff --git a/bug/comment.go b/bug/comment.go
index f7a6eada769684cf479854435fc7ebe7c99f0a81..5db0b18d8a11df3fe2170650149f52dea3807b0c 100644
--- a/bug/comment.go
+++ b/bug/comment.go
@@ -9,6 +9,7 @@ import (
 
 // Comment represent a comment in a Bug
 type Comment struct {
+	id      string
 	Author  identity.Interface
 	Message string
 	Files   []git.Hash
@@ -18,6 +19,21 @@ type Comment struct {
 	UnixTime timestamp.Timestamp
 }
 
+// Id return the Comment identifier
+func (c Comment) Id() string {
+	if c.id == "" {
+		// simply panic as it would be a coding error
+		// (using an id of an identity not stored yet)
+		panic("no id yet")
+	}
+	return c.id
+}
+
+// HumanId return the Comment identifier truncated for human consumption
+func (c Comment) HumanId() string {
+	return FormatHumanID(c.Id())
+}
+
 // FormatTimeRel format the UnixTime of the comment for human consumption
 func (c Comment) FormatTimeRel() string {
 	return humanize.Time(c.UnixTime.Time())
diff --git a/bug/op_add_comment.go b/bug/op_add_comment.go
index 9ecef941efbb0d8bd47b568c1e2fdfdd5df37d8d..c1e0838b2c6984febf238a90e45778f6c8b0c7a9 100644
--- a/bug/op_add_comment.go
+++ b/bug/op_add_comment.go
@@ -29,7 +29,15 @@ func (op *AddCommentOperation) Hash() (git.Hash, error) {
 }
 
 func (op *AddCommentOperation) Apply(snapshot *Snapshot) {
+	hash, err := op.Hash()
+	if err != nil {
+		// Should never error unless a programming error happened
+		// (covered in OpBase.Validate())
+		panic(err)
+	}
+
 	comment := Comment{
+		id:       string(hash),
 		Message:  op.Message,
 		Author:   op.Author,
 		Files:    op.Files,
@@ -38,13 +46,6 @@ func (op *AddCommentOperation) Apply(snapshot *Snapshot) {
 
 	snapshot.Comments = append(snapshot.Comments, comment)
 
-	hash, err := op.Hash()
-	if err != nil {
-		// Should never error unless a programming error happened
-		// (covered in OpBase.Validate())
-		panic(err)
-	}
-
 	item := &AddCommentTimelineItem{
 		CommentTimelineItem: NewCommentTimelineItem(hash, comment),
 	}
diff --git a/bug/op_create.go b/bug/op_create.go
index 42d40f71ea76e253022392971091c6953ed65538..d5852db9a8eb68cd97bab3dc10a9d8ed8a2e61c5 100644
--- a/bug/op_create.go
+++ b/bug/op_create.go
@@ -30,9 +30,17 @@ func (op *CreateOperation) Hash() (git.Hash, error) {
 }
 
 func (op *CreateOperation) Apply(snapshot *Snapshot) {
+	hash, err := op.Hash()
+	if err != nil {
+		// Should never error unless a programming error happened
+		// (covered in OpBase.Validate())
+		panic(err)
+	}
+
 	snapshot.Title = op.Title
 
 	comment := Comment{
+		id:       string(hash),
 		Message:  op.Message,
 		Author:   op.Author,
 		UnixTime: timestamp.Timestamp(op.UnixTime),
@@ -42,13 +50,6 @@ func (op *CreateOperation) Apply(snapshot *Snapshot) {
 	snapshot.Author = op.Author
 	snapshot.CreatedAt = op.Time()
 
-	hash, err := op.Hash()
-	if err != nil {
-		// Should never error unless a programming error happened
-		// (covered in OpBase.Validate())
-		panic(err)
-	}
-
 	snapshot.Timeline = []TimelineItem{
 		&CreateTimelineItem{
 			CommentTimelineItem: NewCommentTimelineItem(hash, comment),
diff --git a/bug/op_create_test.go b/bug/op_create_test.go
index 92ac191dc265d62e96bf972eafeec3dedd5955d2..aa1d8c104b3d60b4c96e24364a31c46a0b3ebf71 100644
--- a/bug/op_create_test.go
+++ b/bug/op_create_test.go
@@ -23,7 +23,12 @@ func TestCreate(t *testing.T) {
 	hash, err := create.Hash()
 	assert.NoError(t, err)
 
-	comment := Comment{Author: rene, Message: "message", UnixTime: timestamp.Timestamp(create.UnixTime)}
+	comment := Comment{
+		id:       string(hash),
+		Author:   rene,
+		Message:  "message",
+		UnixTime: timestamp.Timestamp(create.UnixTime),
+	}
 
 	expected := Snapshot{
 		Title: "title",
diff --git a/bug/op_edit_comment.go b/bug/op_edit_comment.go
index 527b7440dd1e06e2e514c25dc85ed47787d3962f..5a223e01a68e433cfc10070383257886d6fefce1 100644
--- a/bug/op_edit_comment.go
+++ b/bug/op_edit_comment.go
@@ -57,6 +57,7 @@ func (op *EditCommentOperation) Apply(snapshot *Snapshot) {
 	}
 
 	comment := Comment{
+		id:       string(op.Target),
 		Message:  op.Message,
 		Files:    op.Files,
 		UnixTime: timestamp.Timestamp(op.UnixTime),
diff --git a/bug/operation.go b/bug/operation.go
index cc5b0007504d9ba5eb01761502f00b9f28e38598..8e77eed83c97d71584eaad8596343727045acd44 100644
--- a/bug/operation.go
+++ b/bug/operation.go
@@ -60,6 +60,9 @@ func hashRaw(data []byte) git.Hash {
 
 // hash compute the hash of the serialized operation
 func hashOperation(op Operation) (git.Hash, error) {
+	// TODO: this might not be the best idea: if a single bit change in the output of json.Marshal, this will break.
+	// Idea: hash the segment of serialized data (= immutable) instead of the go object in memory
+
 	base := op.base()
 
 	if base.hash != "" {
diff --git a/commands/comment.go b/commands/comment.go
index 08751e275ec25d7e1ae5099b79e5d09bba24900f..cb9f36916da899dafe57f901efa945f2cf261c06 100644
--- a/commands/comment.go
+++ b/commands/comment.go
@@ -39,6 +39,7 @@ func commentsTextOutput(comments []bug.Comment) {
 		}
 
 		fmt.Printf("Author: %s\n", colors.Magenta(comment.Author.DisplayName()))
+		fmt.Printf("Id: %s\n", colors.Cyan(comment.HumanId()))
 		fmt.Printf("Date: %s\n\n", comment.FormatTime())
 		fmt.Println(text.LeftPad(comment.Message, 4))
 	}
diff --git a/identity/identity_stub.go b/identity/identity_stub.go
index 592eab3080d3bd37016a09076c8d161dda4bf649..a2cee0ad6c818c2421f6b06981282cc2d7c00f92 100644
--- a/identity/identity_stub.go
+++ b/identity/identity_stub.go
@@ -20,6 +20,7 @@ type IdentityStub struct {
 }
 
 func (i *IdentityStub) MarshalJSON() ([]byte, error) {
+	// TODO: add a type marker
 	return json.Marshal(struct {
 		Id string `json:"id"`
 	}{