diff --git a/NewCapDesign.md b/NewCapDesign.md
index 0e60207..b6631ce 100644
--- a/NewCapDesign.md
+++ b/NewCapDesign.md
@@ -174,3 +174,6 @@ several lower bounds on the length:
    `tahoe://grid1234/MR/cryptobits`. (#403)
  * permit multiple encodings of the same file (same k, different N) to use
    each other's shares (#678)
+ * be derived from a hash of the plaintext to detect bugs in the decryption
+   or erasure-decoding (#453) and possibly also to be able to easily give
+   users a hash of the plaintext if they want it (#280)