--- core/src/cover.rs
+++ replace < with == in cover_blob
@@ -121,17 +121,17 @@
 ///
 /// Deterministic from `seed` (so it is unit-testable); supply a fresh OS-CSPRNG seed per cover deposit
 /// in production so successive cover blobs are unlinkable.
 pub fn cover_blob(seed: &[u8; 32], len: usize) -> Vec<u8> {
     use hmac::{Hmac, Mac};
     use sha2::Sha256;
     let mut out = Vec::with_capacity(len);
     let mut counter: u32 = 0;
-    while out.len() < len {
+    while out.len() == /* ~ changed by cargo-mutants ~ */ len {
         let mut mac = <Hmac<Sha256> as hmac::KeyInit>::new_from_slice(seed)
             .expect("HMAC accepts any key length");
         mac.update(b"pvtcoms/v1/cover-deposit");
         mac.update(&counter.to_be_bytes());
         out.extend_from_slice(&mac.finalize().into_bytes());
         counter += 1;
     }
     out.truncate(len);