diff --git a/include/relay/CryptoPrimitives.h b/include/relay/CryptoPrimitives.h
index 0af5bbb..278645a 100644
--- a/include/relay/CryptoPrimitives.h
+++ b/include/relay/CryptoPrimitives.h
@@ -10,10 +10,18 @@
 struct PrivateKey {
 
     /// @brief The size of a private key
-    static const int size = 32;
+    static constexpr int size = 32;
 
     uint8_t bytes[size];
 
+    bool isUnset() {
+        for (uint8_t i = 0; i < size; i += 1) {
+            if (bytes[i] != 0) {
+                return false;
+            }
+        }
+        return true;
+    }
 };
 
 /**
@@ -22,10 +30,18 @@ struct PrivateKey {
 struct PublicKey {
 
     /// @brief The size of a public key
-    static const int size = 32;
+    static constexpr int size = 32;
 
     uint8_t bytes[size];
 
+    bool isUnset() {
+        for (uint8_t i = 0; i < size; i += 1) {
+            if (bytes[i] != 0) {
+                return false;
+            }
+        }
+        return true;
+    }
 };
 
 /**
@@ -34,7 +50,7 @@ struct PublicKey {
 struct Signature {
 
     /// @brief The size of a message signature
-    static const int size = 64;
+    static constexpr int size = 64;
 
     uint8_t bytes[size];