diff --git a/libs/apkverify/src/sigutil.rs b/libs/apkverify/src/sigutil.rs
index bfa51c1..395b493 100644
--- a/libs/apkverify/src/sigutil.rs
+++ b/libs/apkverify/src/sigutil.rs
@@ -235,7 +235,7 @@
     use std::fs::File;
     use std::mem::size_of_val;
 
-    use crate::v3::{to_hex_string, APK_SIGNATURE_SCHEME_V3_BLOCK_ID};
+    use crate::v3::APK_SIGNATURE_SCHEME_V3_BLOCK_ID;
 
     const CENTRAL_DIRECTORY_HEADER_SIGNATURE: u32 = 0x02014b50;
 
@@ -276,8 +276,8 @@
         let mut apk_sections = ApkSections::new(apk_file).unwrap();
         let digest = apk_sections.compute_digest(SignatureAlgorithmID::DsaWithSha256).unwrap();
         assert_eq!(
-            "0DF2426EA33AEDAF495D88E5BE0C6A1663FF0A81C5ED12D5B2929AE4B4300F2F",
-            to_hex_string(&digest[..])
+            "0df2426ea33aedaf495d88e5be0c6a1663ff0a81c5ed12d5b2929ae4b4300f2f",
+            hex::encode(&digest[..])
         );
     }
 
diff --git a/libs/apkverify/src/v3.rs b/libs/apkverify/src/v3.rs
index db7d8cc..fcd966b 100644
--- a/libs/apkverify/src/v3.rs
+++ b/libs/apkverify/src/v3.rs
@@ -196,8 +196,8 @@
         ensure!(
             computed == digest.digest.as_ref(),
             "Digest mismatch: computed={:?} vs expected={:?}",
-            to_hex_string(&computed),
-            to_hex_string(&digest.digest),
+            hex::encode(&computed),
+            hex::encode(digest.digest.as_ref()),
         );
 
         // 7. Verify that public key of the first certificate of certificates is identical
@@ -261,8 +261,3 @@
         Ok(PKey::public_key_from_der(raw_public_key.as_ref())?)
     }
 }
-
-#[inline]
-pub(crate) fn to_hex_string(buf: &[u8]) -> String {
-    buf.iter().map(|b| format!("{:02X}", b)).collect()
-}