rename EmptyIdentity -> DerivingRoot

Seems to fit better what the error actually means.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/kem.rs b/src/kem.rs
index a8261b6..091247d 100644
--- a/src/kem.rs
+++ b/src/kem.rs
@@ -298,7 +298,7 @@ impl<M> HybridKem<M> {
     {
         let identity = self.mapper.map_identity(identity)?;
         let Some((child, parent)) = identity.split_last() else {
-            return Err(Error::EmptyIdentity);
+            return Err(Error::DerivingRoot);
         };
         let private_key = self
             .hibe