diff --git a/authfs/Android.bp b/authfs/Android.bp
index a4151c2..8ac600d 100644
--- a/authfs/Android.bp
+++ b/authfs/Android.bp
@@ -19,6 +19,7 @@
         "libclap",
         "libfsverity_digests_proto_rust",
         "libfuse_rust",
+        "libhex",
         "liblibc",
         "liblog_rust",
         "libnix",
diff --git a/authfs/src/main.rs b/authfs/src/main.rs
index 9ff0ae3..e14b771 100644
--- a/authfs/src/main.rs
+++ b/authfs/src/main.rs
@@ -169,21 +169,6 @@
     })
 }
 
-fn from_hex_string(s: &str) -> Result<Vec<u8>> {
-    if s.len() % 2 == 1 {
-        bail!("Incomplete hex string: {}", s);
-    } else {
-        let results = (0..s.len())
-            .step_by(2)
-            .map(|i| {
-                u8::from_str_radix(&s[i..i + 2], 16)
-                    .map_err(|e| anyhow!("Cannot parse hex {}: {}", &s[i..i + 2], e))
-            })
-            .collect::<Result<Vec<_>>>();
-        Ok(results?)
-    }
-}
-
 fn new_remote_verified_file_entry(
     service: file::VirtFdService,
     remote_fd: i32,
@@ -193,7 +178,7 @@
         reader: LazyVerifiedReadonlyFile::prepare_by_fd(
             service,
             remote_fd,
-            from_hex_string(expected_digest)?,
+            hex::decode(expected_digest)?,
         ),
     })
 }
@@ -332,18 +317,3 @@
         std::process::exit(1);
     }
 }
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn parse_hex_string() {
-        assert_eq!(from_hex_string("deadbeef").unwrap(), vec![0xde, 0xad, 0xbe, 0xef]);
-        assert_eq!(from_hex_string("DEADBEEF").unwrap(), vec![0xde, 0xad, 0xbe, 0xef]);
-        assert_eq!(from_hex_string("").unwrap(), Vec::<u8>::new());
-
-        assert!(from_hex_string("deadbee").is_err());
-        assert!(from_hex_string("X").is_err());
-    }
-}