diff --git a/cryptor/cryptor.go b/cryptor/cryptor.go
index c4c1daa..7d92902 100644
--- a/cryptor/cryptor.go
+++ b/cryptor/cryptor.go
@@ -284,6 +284,10 @@ func (encrypted *EncryptedData) wrapKey(records *passvault.Records, clearKey []b
 
 		for _, leftName := range access.LeftNames {
 			for _, rightName := range access.RightNames {
+				if leftName == rightName {
+					continue
+				}
+
 				keyBytes, err := encryptKey(leftName, rightName, clearKey)
 				if err != nil {
 					return err
diff --git a/cryptor/cryptor_test.go b/cryptor/cryptor_test.go
index 011c036..ce7a996 100644
--- a/cryptor/cryptor_test.go
+++ b/cryptor/cryptor_test.go
@@ -9,6 +9,9 @@ import (
 	"encoding/base64"
 	"encoding/json"
 	"testing"
+
+	"github.com/cloudflare/redoctober/keycache"
+	"github.com/cloudflare/redoctober/passvault"
 )
 
 func TestHash(t *testing.T) {
@@ -66,3 +69,55 @@ func TestHash(t *testing.T) {
 	}
 
 }
+
+func TestDuplicates(t *testing.T) {
+	// Setup total names and partitions.
+	names := []string{"Alice", "Bob", "Carl"}
+	recs := make(map[string]passvault.PasswordRecord, 0)
+	left := []string{"Alice", "Bob"}
+	right := []string{"Bob", "Carl"}
+
+	// Add each user to the keycache.
+	cache := keycache.NewCache()
+	records, err := passvault.InitFrom("memory")
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+
+	c := Cryptor{&records, &cache}
+
+	for _, name := range names {
+		pr, err := records.AddNewRecord(name, "weakpassword", true, passvault.DefaultRecordType)
+		if err != nil {
+			t.Fatalf("%v", err)
+		}
+
+		recs[name] = pr
+	}
+
+	// Create candidate encryption of message.
+	ac := AccessStructure{
+		LeftNames:  left,
+		RightNames: right,
+	}
+
+	resp, err := c.Encrypt([]byte("Hello World!"), []string{}, ac)
+	if err != nil {
+		t.Fatalf("Error: %s", err)
+	}
+
+	// Delegate one key at a time and check that decryption fails.
+	for name, pr := range recs {
+		err = cache.AddKeyFromRecord(pr, name, "weakpassword", nil, nil, 2, "1h")
+		if err != nil {
+			t.Fatalf("%v", err)
+		}
+
+		_, _, _, err := c.Decrypt(resp, name)
+		if err == nil {
+			t.Fatalf("That shouldn't have worked!")
+		}
+
+		cache.FlushCache()
+	}
+}