diff --git a/.github/workflows/run-formatter.yml b/.github/workflows/run-formatter.yml
index a7fd7bb8..e0133bc0 100644
--- a/.github/workflows/run-formatter.yml
+++ b/.github/workflows/run-formatter.yml
@@ -3,10 +3,10 @@ name: Run Black Formatter throughout the codebase
 on:
   push:
     paths:
-      - '**.py'
+      - "**.py"
   pull_request:
     paths:
-      - '**.py'
+      - "**.py"
 
 permissions:
   contents: write # Allows auto-fix commits to be made
@@ -23,7 +23,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v5
         with:
-          python-version: '3.10'
+          python-version: "3.12"
 
       - name: Install Black
         run: pip install black
diff --git a/.github/workflows/run-linter.yml b/.github/workflows/run-linter.yml
index ea25ccca..3bf35c74 100644
--- a/.github/workflows/run-linter.yml
+++ b/.github/workflows/run-linter.yml
@@ -20,7 +20,7 @@ jobs:
       - name: Install Python
         uses: actions/setup-python@v5
         with:
-          python-version: '3.10'
+          python-version: '3.12'
           
       - name: Install Ruff
         run: pip install ruff
diff --git a/README.md b/README.md
index 99455b86..c88f4f11 100644
--- a/README.md
+++ b/README.md
@@ -90,7 +90,7 @@ python3 main.py -p MetaMask/metamask-extension -v v11.11.0 -s -pm yarn-berry
 
 2. Differential analysis:
 
-```
+```bash
 python3 main.py -p MetaMask/metamask-extension -v v11.11.0 -vn v11.12.0 -s -d -pm yarn-berry
 ```
 
diff --git a/tool/compare_commits.py b/tool/compare_commits.py
index 472a92e8..9a58dd7a 100644
--- a/tool/compare_commits.py
+++ b/tool/compare_commits.py
@@ -29,6 +29,7 @@ def tag_format(tag, package_name):
         f"v.{tag}",
     ]
 
+    only_package_name, artifact_id_parts = None, None
     if "/" in package_name:  # NPM-based
         only_package_name = package_name.split("/")[1]
     elif ":" in package_name:  # Maven based
diff --git a/tool/compare_packages.py b/tool/compare_packages.py
index ef99b045..130c40cc 100644
--- a/tool/compare_packages.py
+++ b/tool/compare_packages.py
@@ -181,6 +181,15 @@ def get_repo_from_SA(dep_file_1, dep_file_2, SA_old, SA_new):
 
         if versions["message"] == "Upgraded package":
             differences[dep]["category"] = "Upgraded package"
+            # Check code signature changes
+            signature_changes = compare_code_signatures(
+                dep, versions["chosen_v1"], versions["chosen_v2"], SA_old, SA_new
+            )
+            differences[dep]["signature_changes"] = signature_changes
+
+            # If there are signature changes, add it to the category
+            if signature_changes["has_changes"]:
+                differences[dep]["category"] = "Upgraded package with signature changes"
 
             dep_name_version_old = f"{dep}@{versions['chosen_v1']}"
             dep_name_version_new = f"{dep}@{versions['chosen_v2']}"
@@ -338,3 +347,29 @@ def differential(dep_file_1, dep_file_2, SA_1, SA_2):
         upgraded_pkg,
         no_change_pkg,
     )
+
+
+def compare_code_signatures(pkg_name, old_version, new_version, SA_1, SA_2):
+    """Compare code signatures between versions of a package."""
+    old_pkg = f"{pkg_name}@{old_version}"
+    new_pkg = f"{pkg_name}@{new_version}"
+
+    old_signature = SA_1.get(old_pkg, {}).get("code_signature", {})
+    new_signature = SA_2.get(new_pkg, {}).get("code_signature", {})
+
+    changes = {
+        "old_signature_present": old_signature.get("signature_present", False),
+        "new_signature_present": new_signature.get("signature_present", False),
+        "old_signature_valid": old_signature.get("signature_valid", False),
+        "new_signature_valid": new_signature.get("signature_valid", False),
+        "has_changes": False,
+    }
+
+    # Check if there are any changes in signature status
+    if (
+        changes["old_signature_present"] != changes["new_signature_present"]
+        or changes["old_signature_valid"] != changes["new_signature_valid"]
+    ):
+        changes["has_changes"] = True
+
+    return changes
diff --git a/tool/report_diff.py b/tool/report_diff.py
index ad4a4825..e44d547c 100644
--- a/tool/report_diff.py
+++ b/tool/report_diff.py
@@ -163,8 +163,12 @@ def generate_diff_report(data, project_repo_name, release_version_old, release_v
     new_reviewer_commits = df_author_new_reviewer.shape[0]
     both_new_commits = df_author_both_new.shape[0]
 
+    signature_changes = df_all[df_all["category"] == "Upgraded package with signature changes"]
+    signature_changes_number = signature_changes["package_name"].nunique()
+
     counts = {
         ":heavy_exclamation_mark: Downgraded packages": downgraded_number,
+        ":lock: Packages with signature changes": signature_changes_number,
         ":alien: Commits made by both New Authors and Reviewers": both_new_commits,
         ":neutral_face: Commits made by New Authors": new_author_commits,
         ":see_no_evil: Commits approved by New Reviewers": new_reviewer_commits,
@@ -195,6 +199,22 @@ def generate_diff_report(data, project_repo_name, release_version_old, release_v
             f.write("</details>")
             f.write("\n")
 
+        if signature_changes_number > 0:
+            f.write("\n")
+            f.write(
+                f"""
+    <details>
+        <summary>Packages with signature changes</summary>
+                """
+            )
+            f.write("\n\n\n")
+            selected_columns = ["package_name", "old_version", "new_version", "signature_changes"]
+            signature_changes_df = signature_changes[selected_columns]
+            f.write(signature_changes_df.to_markdown(index=False))
+            f.write("\n")
+            f.write("</details>")
+            f.write("\n")
+
         if both_new_commits > 0:
             f.write("\n")
             f.write(
diff --git a/tool/report_static.py b/tool/report_static.py
index beb44ad0..6d6eccee 100644
--- a/tool/report_static.py
+++ b/tool/report_static.py
@@ -15,6 +15,8 @@
     "deprecated": ["yarn-classic", "yarn-berry", "pnpm", "npm"],
     "forked_package": ["yarn-classic", "yarn-berry", "pnpm", "npm", "maven"],
     "provenance": ["yarn-classic", "yarn-berry", "pnpm", "npm"],
+    "code_signature": ["yarn-classic", "yarn-berry", "pnpm", "npm", "maven"],
+    "invalid_code_signature": ["yarn-classic", "yarn-berry", "pnpm", "npm", "maven"],
 }
 
 
@@ -46,6 +48,8 @@ def create_dataframe(data):
             "deprecated_in_version": package_data.get("package_info", {}).get("deprecated_in_version"),
             "provenance_in_version": package_data.get("package_info", {}).get("provenance_in_version"),
             "all_deprecated": package_data.get("package_info", {}).get("all_deprecated", None),
+            "signature_present": package_data.get("code_signature").get("signature_present"),
+            "signature_valid": package_data.get("code_signature").get("signature_valid"),
             "github_url": github_exists_data.get("github_url", "Could not find repo from package registry"),
             "github_exists": github_exists_data.get("github_exists", None),
             "github_redirected": github_exists_data.get("github_redirected", None),
@@ -114,6 +118,18 @@ def write_summary(df, project_name, release_version, package_manager, filename,
             "provenance_in_version",
         ],
     ]
+    code_signature_df = df.loc[
+        df["signature_present"] == False,
+        [
+            "signature_present",
+        ],
+    ]
+    invalid_code_signature_df = df.loc[
+        (df["signature_present"] == True) & (df["signature_valid"] == False),
+        [
+            "signature_valid",
+        ],
+    ]
 
     common_counts = {
         "### Total packages in the supply chain": len(df),
@@ -125,6 +141,8 @@ def write_summary(df, project_name, release_version, package_manager, filename,
         "release_tag_not_found": f":wrench: Packages with accessible source code repos but inaccessible GitHub tags(⚠️⚠️⚠️) {(release_tag_not_found_df.shape[0])}",
         "deprecated": f":x: Packages that are deprecated(⚠️⚠️) {(df['deprecated_in_version'] == True).sum()}",
         "forked_package": f":cactus: Packages that are forks(⚠️⚠️) {(df['is_fork'] == True).sum()}",
+        "code_signature": f":lock: Packages with no code signature(⚠️⚠️) {(code_signature_df.shape[0])}",
+        "invalid_code_signature": f":pencil: Packages with an existing but invalid code signature(⚠️⚠️) {((invalid_code_signature_df.shape[0]))}",
         "provenance": f":black_square_button: Packages without provenance(⚠️) {(df['provenance_in_version'] == False).sum()}",
     }
 
@@ -270,6 +288,38 @@ def write_summary(df, project_name, release_version, package_manager, filename,
         else:
             md_file.write("\nAll packages have provenance.\n")
 
+        if not code_signature_df.empty:
+            md_file.write(
+                f"""
+<details>
+    <summary>List of packages without code signature({(code_signature_df.shape[0])})</summary>
+        """
+            )
+            md_file.write("\n\n\n")
+            markdown_text = code_signature_df.reset_index().to_markdown(index=False)
+            md_file.write(markdown_text)
+            md_file.write("\n</details>\n")
+        elif package_manager not in SUPPORTED_SMELLS["code_signature"]:
+            md_file.write(f"\nThe package manager ({package_manager}) does not support checking for code signature.\n")
+        else:
+            md_file.write("\nAll packages have code signature.\n")
+
+        if not invalid_code_signature_df.empty:
+            md_file.write(
+                f"""
+<details>
+    <summary>List of packages with an existing but invalid code signature({(invalid_code_signature_df.shape[0])})</summary>
+        """
+            )
+            md_file.write("\n\n\n")
+            markdown_text = invalid_code_signature_df.reset_index().to_markdown(index=False)
+            md_file.write(markdown_text)
+            md_file.write("\n</details>\n")
+        elif package_manager not in SUPPORTED_SMELLS["code_signature"]:
+            md_file.write(f"\nThe package manager ({package_manager}) does not support checking for code signature.\n")
+        else:
+            md_file.write("\nAll packages have valid code signature.\n")
+
         md_file.write("\n### Call to Action:\n")
         md_file.write(
             """
diff --git a/tool/static_analysis.py b/tool/static_analysis.py
index 0f836388..4f9db8b2 100644
--- a/tool/static_analysis.py
+++ b/tool/static_analysis.py
@@ -6,6 +6,8 @@
 from tqdm import tqdm
 
 import requests
+import subprocess
+import re
 
 import tool_config
 from compare_commits import tag_format as construct_tag_format
@@ -101,6 +103,61 @@ def check_maven(package, package_version):
         logging.error(f"Package manager {pm} not supported.")
 
 
+def check_code_signature(package_name, package_version, pm):
+    # TODO: caching this somehow would be nice
+    # TODO: find a package where we can check this, because with spoon everything is fine
+    def check_maven_signature(package_name, package_version):
+        # Construct the command
+        command = f"mvn org.simplify4u.plugins:pgpverify-maven-plugin:show -Dartifact={package_name}:{package_version}"
+
+        # Run the command
+        output = subprocess.run(command, shell=True, capture_output=True, text=True)
+
+        # Regular expression to extract the PGP signature section
+        pgp_signature_pattern = re.compile(r"PGP signature:\n(?:[ \t]*.+\n)*?[ \t]*status:\s*(\w+)", re.MULTILINE)
+        match = pgp_signature_pattern.search(output.stdout)
+        if match:
+            # Extract the status
+            status = match.group(1).strip().lower()
+            return {"signature_present": True, "signature_valid": status == "valid"}
+
+        # If no match is found, return no PGP signature present
+        return {"signature_present": False, "signature_valid": False}
+
+    def check_npm_signature(package, package_version):
+        # NOTE: for future reference, NPM migrated from PGP signatures to ECDSA registry signatures
+        # PGP-based registry signatures were deprecated on April 25th, 2023
+        try:
+            response = requests.get(f"https://registry.npmjs.org/{package}", timeout=20)
+            response.raise_for_status()
+
+            data = response.json()
+            version_info = data.get("versions", {}).get(package_version, {})
+
+            # Check for signature in dist metadata
+            dist_info = version_info.get("dist", {})
+            signatures = dist_info.get("signatures", [])
+
+            if signatures:
+                valid_signatures = [sig for sig in signatures if sig.get("keyid") and sig.get("sig")]
+                return {"signature_present": True, "signature_valid": len(valid_signatures) > 0}
+
+            return {"signature_present": False, "signature_valid": False}
+
+        except requests.RequestException as e:
+            logging.error(f"Error checking NPM signature: {str(e)}")
+            return {"signature_present": False, "signature_valid": False}
+
+    if pm == "maven":
+        return check_maven_signature(package_name, package_version)
+    elif pm in ("yarn-berry", "yarn-classic", "pnpm", "npm"):
+        return check_npm_signature(package_name, package_version)
+    else:
+        # log stuff
+        # blow up
+        logging.error(f"Package manager {pm} not supported.")
+
+
 def api_constructor(package_name, repository):
     repo_url = repository.replace("https://", "").replace("http://", "").replace("/issues", "")
 
@@ -438,6 +495,10 @@ def analyze_package_data(package, repo_url, pm, check_match=False):
         package_info["provenance"] = package_infos.get("provenance_in_version")
         package_info["package_info"] = package_infos
 
+        # Code signature checks
+        print(f"[INFO] Checking code signature for {package_name}...")
+        package_info["code_signature"] = check_code_signature(package_name, package_version, pm)
+
         if "Could not find" in repo_url:
             package_info["github_exists"] = {"github_url": "No_repo_info_found"}
         elif "not github" in repo_url:
@@ -482,7 +543,7 @@ def get_static_data(folder, packages_data, pm, check_match=False):
     with tqdm(total=len(packages_data), desc="Analyzing packages") as pbar:
         for package, repo_urls in packages_data.items():
             # print(f"Analyzing {package}")
-            tqdm.write(f"{package}")
+            tqdm.write(f"[INFO] Currently analyzing {package}")
             repo_url = repo_urls.get("github", "")
             analyzed_data, error = analyze_package_data(package, repo_url, pm, check_match=check_match)
             pbar.update(1)