diff --git a/cubetoken/LICENSE.md b/cubetoken/LICENSE.md
new file mode 100644
index 0000000..7e792db
--- /dev/null
+++ b/cubetoken/LICENSE.md
@@ -0,0 +1,28 @@
+Copyright (c) {2016,...}, 2023 Michael Paepcke. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+1. Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+
+2. Redistributions in binary form must reproduce the above copyright
+   notice, this list of conditions and the following disclaimer in the
+   documentation and/or other materials provided with the distribution.
+
+3. Neither the name of the copyright holder nor the names of its
+   contributors may be used to endorse or promote products derived from
+   this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/cubetoken/api.go b/cubetoken/api.go
index eb7d0ce..9728c75 100644
--- a/cubetoken/api.go
+++ b/cubetoken/api.go
@@ -1,7 +1,6 @@
-// Package cubetoken provides and [complex] [multi-] input to hash KDF [key derivation function]
+// Package cubetoken provides a complex KDF function
 package cubetoken
 
-// import
 import (
 	"paepcke.de/signify"
 	"paepcke.de/sphincs"
diff --git a/cubetoken/core.go b/cubetoken/core.go
index e4394f6..ad70709 100644
--- a/cubetoken/core.go
+++ b/cubetoken/core.go
@@ -1,4 +1,3 @@
-// package cubetoken ...
 package cubetoken
 
 // generate ...
diff --git a/cubetoken/hash.go b/cubetoken/hash.go
index 7d95123..6e8d2d4 100644
--- a/cubetoken/hash.go
+++ b/cubetoken/hash.go
@@ -1,4 +1,3 @@
-// package cubetoken
 package cubetoken
 
 // import
diff --git a/cubetoken/io.go b/cubetoken/io.go
index a35d47e..40f60dc 100644
--- a/cubetoken/io.go
+++ b/cubetoken/io.go
@@ -1,7 +1,5 @@
-// package cubetoken
 package cubetoken
 
-// import
 import (
 	"os"
 	"sync"
diff --git a/cubetoken/kdf.go b/cubetoken/kdf.go
index 024e2e8..96d399b 100644
--- a/cubetoken/kdf.go
+++ b/cubetoken/kdf.go
@@ -1,7 +1,5 @@
-// package cubetoken ...
 package cubetoken
 
-// import
 import (
 	"crypto/sha512"
 	"hash"