diff --git a/libs/apkverify/Android.bp b/libs/apkverify/Android.bp
index 9bb8f8e..78192d2 100644
--- a/libs/apkverify/Android.bp
+++ b/libs/apkverify/Android.bp
@@ -15,6 +15,7 @@
         "liblog_rust",
         "libnum_traits",
         "libopenssl",
+        "libserde",
         "libzip",
     ],
     proc_macros: ["libnum_derive"],
diff --git a/libs/apkverify/src/algorithms.rs b/libs/apkverify/src/algorithms.rs
index 9a5144c..622df3b 100644
--- a/libs/apkverify/src/algorithms.rs
+++ b/libs/apkverify/src/algorithms.rs
@@ -18,16 +18,18 @@
 
 use anyhow::{ensure, Result};
 use num_derive::{FromPrimitive, ToPrimitive};
+use num_traits::ToPrimitive;
 use openssl::hash::MessageDigest;
 use openssl::pkey::{self, PKey};
 use openssl::rsa::Padding;
 use openssl::sign::Verifier;
+use serde::{Deserialize, Serialize};
 
 /// [Signature Algorithm IDs]: https://source.android.com/docs/security/apksigning/v2#signature-algorithm-ids
 /// [SignatureAlgorithm.java]: (tools/apksig/src/main/java/com/android/apksig/internal/apk/SignatureAlgorithm.java)
 ///
 /// Some of the algorithms are not implemented. See b/197052981.
-#[derive(Clone, Debug, Eq, PartialEq, FromPrimitive, ToPrimitive)]
+#[derive(Serialize, Deserialize, Clone, Debug, Eq, PartialEq, FromPrimitive, ToPrimitive)]
 #[repr(u32)]
 pub enum SignatureAlgorithmID {
     /// RSASSA-PSS with SHA2-256 digest, SHA2-256 MGF1, 32 bytes of salt, trailer: 0xbc, content
@@ -77,6 +79,11 @@
 }
 
 impl SignatureAlgorithmID {
+    /// Converts the signature algorithm ID to the corresponding u32.
+    pub fn to_u32(&self) -> u32 {
+        ToPrimitive::to_u32(self).expect("Unsupported algorithm for to_u32.")
+    }
+
     pub(crate) fn new_verifier<'a>(
         &self,
         public_key: &'a PKey<pkey::Public>,
@@ -86,7 +93,7 @@
                 self,
                 SignatureAlgorithmID::DsaWithSha256 | SignatureAlgorithmID::VerityDsaWithSha256
             ),
-            "TODO(b/197052981): Algorithm '{:#?}' is not implemented.",
+            "TODO(b/197052981): Algorithm '{:?}' is not implemented.",
             self
         );
         ensure!(public_key.id() == self.pkey_id(), "Public key has the wrong ID");
diff --git a/libs/apkverify/src/sigutil.rs b/libs/apkverify/src/sigutil.rs
index fabb8e6..bfa51c1 100644
--- a/libs/apkverify/src/sigutil.rs
+++ b/libs/apkverify/src/sigutil.rs
@@ -16,10 +16,6 @@
 
 //! Utilities for Signature Verification
 
-// TODO(b/246254355): Remove this once we migrate all the usages of
-// raw signature algorithm id to the enum.
-#![allow(dead_code)]
-
 use anyhow::{anyhow, ensure, Error, Result};
 use byteorder::{LittleEndian, ReadBytesExt};
 use bytes::{Buf, BufMut, Bytes, BytesMut};
@@ -33,19 +29,9 @@
 const APK_SIG_BLOCK_MIN_SIZE: u32 = 32;
 const APK_SIG_BLOCK_MAGIC: u128 = 0x3234206b636f6c4220676953204b5041;
 
-// TODO(b/246254355): Migrates usages of raw signature algorithm id to the enum.
-pub const SIGNATURE_RSA_PSS_WITH_SHA256: u32 = 0x0101;
-pub const SIGNATURE_RSA_PSS_WITH_SHA512: u32 = 0x0102;
-pub const SIGNATURE_RSA_PKCS1_V1_5_WITH_SHA256: u32 = 0x0103;
-pub const SIGNATURE_RSA_PKCS1_V1_5_WITH_SHA512: u32 = 0x0104;
-pub const SIGNATURE_ECDSA_WITH_SHA256: u32 = 0x0201;
-pub const SIGNATURE_ECDSA_WITH_SHA512: u32 = 0x0202;
-pub const SIGNATURE_DSA_WITH_SHA256: u32 = 0x0301;
-pub const SIGNATURE_VERITY_RSA_PKCS1_V1_5_WITH_SHA256: u32 = 0x0421;
-pub const SIGNATURE_VERITY_ECDSA_WITH_SHA256: u32 = 0x0423;
-pub const SIGNATURE_VERITY_DSA_WITH_SHA256: u32 = 0x0425;
-
 const CHUNK_SIZE_BYTES: u64 = 1024 * 1024;
+const CHUNK_HEADER_TOP: &[u8] = &[0x5a];
+const CHUNK_HEADER_MID: &[u8] = &[0xa5];
 
 /// The [APK structure] has four major sections:
 ///
@@ -166,9 +152,6 @@
     message_digest: MessageDigest,
 }
 
-const CHUNK_HEADER_TOP: &[u8] = &[0x5a];
-const CHUNK_HEADER_MID: &[u8] = &[0xa5];
-
 impl Digester {
     // v2/v3 digests are computed after prepending "header" byte and "size" info.
     fn digest(&self, data: &[u8], header: &[u8], size: u32) -> Result<DigestBytes> {
diff --git a/libs/apkverify/src/v3.rs b/libs/apkverify/src/v3.rs
index 2f8fb45..875fec8 100644
--- a/libs/apkverify/src/v3.rs
+++ b/libs/apkverify/src/v3.rs
@@ -127,7 +127,7 @@
 /// Gets the v4 [apk_digest].
 ///
 /// [apk_digest]: https://source.android.com/docs/security/apksigning/v4#apk-digest
-pub fn pick_v4_apk_digest<R: Read + Seek>(apk: R) -> Result<(u32, Box<[u8]>)> {
+pub fn pick_v4_apk_digest<R: Read + Seek>(apk: R) -> Result<(SignatureAlgorithmID, Box<[u8]>)> {
     let mut sections = ApkSections::new(apk)?;
     let mut block = sections.find_signature(APK_SIGNATURE_SCHEME_V3_BLOCK_ID)?;
     let signers = block.read::<Signers>()?;
@@ -151,7 +151,7 @@
             .context("No supported signatures found")?)
     }
 
-    fn pick_v4_apk_digest(&self) -> Result<(u32, Box<[u8]>)> {
+    fn pick_v4_apk_digest(&self) -> Result<(SignatureAlgorithmID, Box<[u8]>)> {
         let strongest = self.strongest_signature()?;
         let signed_data: SignedData = self.signed_data.slice(..).read()?;
         let digest = signed_data
@@ -159,7 +159,10 @@
             .iter()
             .find(|&dig| dig.signature_algorithm_id == strongest.signature_algorithm_id)
             .context("Digest not found")?;
-        Ok((digest.signature_algorithm_id, digest.digest.as_ref().to_vec().into_boxed_slice()))
+        // TODO(b/246254355): Remove this conversion once Digest contains the enum SignatureAlgorithmID
+        let signature_algorithm_id = SignatureAlgorithmID::from_u32(digest.signature_algorithm_id)
+            .context("Unsupported algorithm")?;
+        Ok((signature_algorithm_id, digest.digest.as_ref().to_vec().into_boxed_slice()))
     }
 
     /// The steps in this method implements APK Signature Scheme v3 verification step 3.
@@ -297,7 +300,7 @@
     fn test_pick_v4_apk_digest_only_with_v3_dsa_sha256() {
         check_v4_apk_digest(
             "tests/data/v3-only-with-dsa-sha256-1024.apk",
-            SIGNATURE_DSA_WITH_SHA256,
+            SignatureAlgorithmID::DsaWithSha256,
             "0DF2426EA33AEDAF495D88E5BE0C6A1663FF0A81C5ED12D5B2929AE4B4300F2F",
         );
     }
@@ -306,13 +309,17 @@
     fn test_pick_v4_apk_digest_only_with_v3_pkcs1_sha512() {
         check_v4_apk_digest(
             "tests/data/v3-only-with-rsa-pkcs1-sha512-1024.apk",
-            SIGNATURE_RSA_PKCS1_V1_5_WITH_SHA512,
+            SignatureAlgorithmID::RsaPkcs1V15WithSha512,
             "9B9AE02DA60B18999BF541790F00D380006FDF0655C3C482AA0BB0AF17CF7A42\
              ECF56B973518546C9080B2FEF83027E895ED2882BFC88EA19790BBAB29AF53B3",
         );
     }
 
-    fn check_v4_apk_digest(apk_filename: &str, expected_algorithm: u32, expected_digest: &str) {
+    fn check_v4_apk_digest(
+        apk_filename: &str,
+        expected_algorithm: SignatureAlgorithmID,
+        expected_digest: &str,
+    ) {
         let apk_file = File::open(apk_filename).unwrap();
         let (signature_algorithm_id, apk_digest) = pick_v4_apk_digest(apk_file).unwrap();
 
diff --git a/libs/idsig/src/apksigv4.rs b/libs/idsig/src/apksigv4.rs
index 92f8963..c1b6495 100644
--- a/libs/idsig/src/apksigv4.rs
+++ b/libs/idsig/src/apksigv4.rs
@@ -159,11 +159,7 @@
 
         apk.seek(SeekFrom::Start(start))?;
         let (signature_algorithm_id, apk_digest) = pick_v4_apk_digest(apk)?;
-        // TODO(b/246254355): Removes this conversion once pick_v4_apk_digest
-        // returns the enum SignatureAlgorithmID instead of raw integer.
-        ret.signing_info.signature_algorithm_id =
-            SignatureAlgorithmID::from_u32(signature_algorithm_id)
-                .context("Unsupported algorithm")?;
+        ret.signing_info.signature_algorithm_id = signature_algorithm_id;
         ret.signing_info.apk_digest = apk_digest;
         // TODO(jiyong): add a signature to the signing_info struct
 
@@ -261,7 +257,7 @@
         write_sized_array(&mut w, &self.x509_certificate)?;
         write_sized_array(&mut w, &self.additional_data)?;
         write_sized_array(&mut w, &self.public_key)?;
-        w.write_u32::<LittleEndian>(self.signature_algorithm_id.to_u32().unwrap())?;
+        w.write_u32::<LittleEndian>(self.signature_algorithm_id.to_u32())?;
         write_sized_array(&mut w, &self.signature)?;
 
         // Determine the size of signing_info, and write it in front of the struct where the value