diff --git a/crossfire/not-crypto.rkt b/crossfire/not-crypto.rkt
index 74b9851..b4812f5 100644
--- a/crossfire/not-crypto.rkt
+++ b/crossfire/not-crypto.rkt
@@ -105,3 +105,9 @@
 (define (crypto-lock-make-nonce)
   (crypto-random-bytes 24))
 (provide crypto-lock-make-key crypto-lock-make-nonce)
+
+;; misc
+
+(define/ffi crypto-wipe
+  (_fun (buf : _u8vector) (sz : _size = (u8vector-length buf)) -> _void))
+(provide crypto-wipe)
diff --git a/static/run.rkt b/static/run.rkt
index a6e5da8..95f822e 100644
--- a/static/run.rkt
+++ b/static/run.rkt
@@ -19,3 +19,12 @@
 (require "../crossfire/not-crypto.rkt")
 
 (crypto-sign-public-key #"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa")
+
+(define key (crypto-lock-make-key))
+(define nonce (crypto-lock-make-nonce))
+(define pt #"hello world")
+
+(define-values [ct mac] (crypto-lock key nonce pt))
+
+(displayln (crypto-unlock key nonce mac ct))
+(displayln (crypto-unlock key nonce mac (bytes-append ct #"abcd")))