diff --git a/rust/k210-shared/src/soc/aes.rs b/rust/k210-shared/src/soc/aes.rs
index 36e272c..24950da 100644
--- a/rust/k210-shared/src/soc/aes.rs
+++ b/rust/k210-shared/src/soc/aes.rs
@@ -53,6 +53,7 @@ pub fn run(
         tag: &mut [u8],
     )
 {
+    assert!(ind.len() != 0);
     match cipher_mode {
         cipher_mode::ECB => assert!(iv.len() == 0 && aad.len() == 0),
         cipher_mode::CBC => assert!(iv.len() == 16 && aad.len() == 0),