diff --git a/tools/releasetools/check_target_files_signatures.py b/tools/releasetools/check_target_files_signatures.py
index 8c1bb9a..6e02e4d 100755
--- a/tools/releasetools/check_target_files_signatures.py
+++ b/tools/releasetools/check_target_files_signatures.py
@@ -120,19 +120,18 @@
   def __init__(self):
     self.certs = {}
 
-  def Add(self, cert, name=None):
-    if cert in self.certs:
+  def Add(self, cert_digest, subject, name=None):
+    if cert_digest in self.certs:
       if name:
-        self.certs[cert] = self.certs[cert] + "," + name
+        self.certs[cert_digest] = self.certs[cert_digest] + "," + name
     else:
       if name is None:
-        name = "unknown cert %s (%s)" % (common.sha1(cert).hexdigest()[:12],
-                                         GetCertSubject(cert))
-      self.certs[cert] = name
+        name = "unknown cert %s (%s)" % (cert_digest[:12], subject)
+      self.certs[cert_digest] = name
 
-  def Get(self, cert):
-    """Return the name for a given cert."""
-    return self.certs.get(cert, None)
+  def Get(self, cert_digest):
+    """Return the name for a given cert digest."""
+    return self.certs.get(cert_digest, None)
 
   def FindLocalCerts(self):
     to_load = []
@@ -148,7 +147,10 @@
         cert = common.ParseCertificate(f.read())
       name, _ = os.path.splitext(i)
       name, _ = os.path.splitext(name)
-      self.Add(cert, name)
+
+      cert_sha1 = common.sha1(cert).hexdigest()
+      cert_subject = GetCertSubject(cert)
+      self.Add(cert_sha1, cert_subject, name)
 
 
 ALL_CERTS = CertDB()
@@ -184,7 +186,7 @@
 
   def __init__(self, full_filename, filename):
     self.filename = filename
-    self.certs = None
+    self.cert_digests = frozenset()
     self.shared_uid = None
     self.package = None
 
@@ -195,22 +197,68 @@
     finally:
       Pop()
 
-  def RecordCerts(self, full_filename):
-    out = set()
+  def ReadCertsDeprecated(self, full_filename):
+    print("reading certs in deprecated way for {}".format(full_filename))
+    cert_digests = set()
     with zipfile.ZipFile(full_filename) as apk:
-      pkcs7 = None
       for info in apk.infolist():
         filename = info.filename
         if (filename.startswith("META-INF/") and
             info.filename.endswith((".DSA", ".RSA"))):
           pkcs7 = apk.read(filename)
           cert = CertFromPKCS7(pkcs7, filename)
-          out.add(cert)
-          ALL_CERTS.Add(cert)
-      if not pkcs7:
-        AddProblem("no signature")
+          if not cert:
+            continue
+          cert_sha1 = common.sha1(cert).hexdigest()
+          cert_subject = GetCertSubject(cert)
+          ALL_CERTS.Add(cert_sha1, cert_subject)
+          cert_digests.add(cert_sha1)
+    if not cert_digests:
+      AddProblem("No signature found")
+      return
+    self.cert_digests = frozenset(cert_digests)
 
-    self.certs = frozenset(out)
+  def RecordCerts(self, full_filename):
+    """Parse and save the signature of an apk file."""
+
+    # Dump the cert info with apksigner
+    cmd = ["apksigner", "verify", "--print-certs", full_filename]
+    p = common.Run(cmd, stdout=subprocess.PIPE)
+    output, _ = p.communicate()
+    if p.returncode != 0:
+      self.ReadCertsDeprecated(full_filename)
+      return
+
+    # Sample output:
+    # Signer #1 certificate DN: ...
+    # Signer #1 certificate SHA-256 digest: ...
+    # Signer #1 certificate SHA-1 digest: ...
+    # ...
+    certs_info = {}
+    certificate_regex = re.compile(r"(Signer #[0-9]+) (certificate .*):(.*)")
+    for line in output.splitlines():
+      m = certificate_regex.match(line)
+      if not m:
+        continue
+      signer, key, val = m.group(1), m.group(2), m.group(3)
+      if certs_info.get(signer):
+        certs_info[signer].update({key.strip(): val.strip()})
+      else:
+        certs_info.update({signer: {key.strip(): val.strip()}})
+    if not certs_info:
+      AddProblem("Failed to parse cert info")
+      return
+
+    cert_digests = set()
+    for signer, props in certs_info.items():
+      subject = props.get("certificate DN")
+      digest = props.get("certificate SHA-1 digest")
+      if not subject or not digest:
+        AddProblem("Failed to parse cert subject or digest")
+        return
+      ALL_CERTS.Add(digest, subject)
+      cert_digests.add(digest)
+    self.cert_digests = frozenset(cert_digests)
 
   def ReadManifest(self, full_filename):
     p = common.Run(["aapt2", "dump", "xmltree", full_filename, "--file",
@@ -316,8 +364,8 @@
       print("uid %s is shared by packages with different cert sets:" % (uid,))
       for apk in apks:
         print("%-*s  [%s]" % (self.max_pkg_len, apk.package, apk.filename))
-        for cert in apk.certs:
-          print("   ", ALL_CERTS.Get(cert))
+        for digest in apk.cert_digests:
+          print("   ", ALL_CERTS.Get(digest))
       print()
 
   def CheckExternalSignatures(self):
@@ -328,25 +376,30 @@
         # predexopting.  Consider it an error if this app is now
         # signed with any key that is present in our tree.
         apk = self.apks_by_basename[apk_filename]
-        name = ALL_CERTS.Get(apk.cert)
-        if not name.startswith("unknown "):
+        signed_with_external = False
+        for digest in apk.cert_digests:
+          name = ALL_CERTS.Get(digest)
+          if name and name.startswith("unknown "):
+            signed_with_external = True
+
+        if not signed_with_external:
           Push(apk.filename)
           AddProblem("hasn't been signed with EXTERNAL cert")
           Pop()
 
   def PrintCerts(self):
     """Display a table of packages grouped by cert."""
-    by_cert = {}
+    by_digest = {}
     for apk in self.apks.values():
-      for cert in apk.certs:
-        by_cert.setdefault(cert, []).append((apk.package, apk))
+      for digest in apk.cert_digests:
+        by_digest.setdefault(digest, []).append((apk.package, apk))
 
-    order = [(-len(v), k) for (k, v) in by_cert.items()]
+    order = [(-len(v), k) for (k, v) in by_digest.items()]
     order.sort()
 
-    for _, cert in order:
-      print("%s:" % (ALL_CERTS.Get(cert),))
-      apks = by_cert[cert]
+    for _, digest in order:
+      print("%s:" % (ALL_CERTS.Get(digest),))
+      apks = by_digest[digest]
       apks.sort()
       for _, apk in apks:
         if apk.shared_uid:
@@ -366,15 +419,15 @@
 
     max_pkg_len = max(self.max_pkg_len, other.max_pkg_len)
 
-    by_certpair = {}
+    by_digestpair = {}
 
     for i in all_apks:
       if i in self.apks:
         if i in other.apks:
           # in both; should have same set of certs
-          if self.apks[i].certs != other.apks[i].certs:
-            by_certpair.setdefault((other.apks[i].certs,
-                                    self.apks[i].certs), []).append(i)
+          if self.apks[i].cert_digests != other.apks[i].cert_digests:
+            by_digestpair.setdefault((other.apks[i].cert_digests,
+                                      self.apks[i].cert_digests), []).append(i)
         else:
           print("%s [%s]: new APK (not in comparison target_files)" % (
               i, self.apks[i].filename))
@@ -383,10 +436,10 @@
           print("%s [%s]: removed APK (only in comparison target_files)" % (
               i, other.apks[i].filename))
 
-    if by_certpair:
+    if by_digestpair:
       AddProblem("some APKs changed certs")
       Banner("APK signing differences")
-      for (old, new), packages in sorted(by_certpair.items()):
+      for (old, new), packages in sorted(by_digestpair.items()):
         for i, o in enumerate(old):
           if i == 0:
             print("was", ALL_CERTS.Get(o))