diff --git a/cbscore/src/cbscore/builder/builder.py b/cbscore/src/cbscore/builder/builder.py
index 5a838c25..984f2b57 100644
--- a/cbscore/src/cbscore/builder/builder.py
+++ b/cbscore/src/cbscore/builder/builder.py
@@ -64,6 +64,7 @@ class Builder:
     ccache_path: Path | None
     skip_build: bool
     force: bool
+    tls_verify: bool
 
     def __init__(
         self,
@@ -72,6 +73,7 @@ def __init__(
         *,
         skip_build: bool = False,
         force: bool = False,
+        tls_verify: bool = True
     ) -> None:
         self.desc = desc
         self.config = config
@@ -82,6 +84,7 @@ def __init__(
         self.ccache_path = config.paths.ccache
         self.skip_build = skip_build
         self.force = force
+        self.tls_verify = tls_verify
 
         try:
             vault_config = self.config.get_vault_config()
@@ -109,7 +112,7 @@ async def run(self) -> None:
             raise BuilderError(msg=msg) from e
 
         container_img_uri = get_container_canonical_uri(self.desc)
-        if skopeo_image_exists(container_img_uri, self.secrets):
+        if skopeo_image_exists(container_img_uri, self.secrets, tls_verify=self.tls_verify):
             logger.info(f"image '{container_img_uri}' already exists -- do not build!")
             return
         else:
diff --git a/cbscore/src/cbscore/builder/prepare.py b/cbscore/src/cbscore/builder/prepare.py
index 7db78250..7c6c1119 100644
--- a/cbscore/src/cbscore/builder/prepare.py
+++ b/cbscore/src/cbscore/builder/prepare.py
@@ -105,16 +105,19 @@ async def _cb(s: str) -> None:
             raise BuilderError(msg="unable to install dependencies")
 
         # install cosign rpm
-        rc, _, stderr = await async_run_cmd(
+        rc, stdout, stderr = await async_run_cmd(
             [
                 "rpm",
                 "-Uvh",
                 "https://github.com/sigstore/cosign/releases/download/v2.4.3/"
                 + "cosign-2.4.3-1.x86_64.rpm",
             ],
-            outcb=_cb,
         )
-        if rc != 0:
+        logger.debug(stdout)
+        if rc == 2 and re.match(".*already installed.*", stderr):
+            msg = f'skip install cosign. allready installed'
+            logger.debug(msg)
+        elif rc != 0:
             msg = f"error installing cosign package: {stderr}"
             logger.error(msg)
             raise BuilderError(msg)
diff --git a/cbscore/src/cbscore/cmds/builds.py b/cbscore/src/cbscore/cmds/builds.py
index 84a56a4f..44ae6fb7 100644
--- a/cbscore/src/cbscore/cmds/builds.py
+++ b/cbscore/src/cbscore/cmds/builds.py
@@ -124,6 +124,11 @@
     is_flag=True,
     default=False,
 )
+@click.option(
+    "--tls-verify",
+    help="Require HTTPS and verify certificates when talking to the container registry or daemon.",
+    default=True,
+)
 @pass_ctx
 def cmd_build(
     ctx: Ctx,
@@ -136,6 +141,7 @@ def cmd_build(
     log_file_path: Path | None,
     skip_build: bool,
     force: bool,
+    tls_verify: bool,
 ) -> None:
     assert ctx.config_path
 
@@ -192,6 +198,7 @@ def cmd_build(
                 log_file_path=log_file_path,
                 skip_build=skip_build,
                 force=force,
+                tls_verify=tls_verify,
             )
         )
 
@@ -245,12 +252,18 @@ def cmd_runner_grp() -> None:
     is_flag=True,
     default=False,
 )
+@click.option(
+    "--tls-verify",
+    help="Require HTTPS and verify certificates when talking to the container registry or daemon.",
+    default=True,
+)
 @with_config
 def cmd_runner_build(
     config: Config,
     desc_path: Path,
     skip_build: bool,
     force: bool,
+    tls_verify: bool,
 ) -> None:
     upload_to_str = (
         config.storage.s3.url
@@ -285,6 +298,7 @@ def cmd_runner_build(
          registry: {registry_str}
        skip build: {skip_build}
             force: {force}
+       tls-verify: {tls_verify}
 """)
 
     if not desc_path.exists():
@@ -303,6 +317,7 @@ def cmd_runner_build(
             config,
             skip_build=skip_build,
             force=force,
+            tls_verify=tls_verify,
         )
     except BuilderError as e:
         logger.error(f"unable to initialize builder: {e}")
diff --git a/cbscore/src/cbscore/images/signing.py b/cbscore/src/cbscore/images/signing.py
index 8e017675..a2373246 100644
--- a/cbscore/src/cbscore/images/signing.py
+++ b/cbscore/src/cbscore/images/signing.py
@@ -36,34 +36,53 @@ def __str__(self) -> str:
         return f"Signing Error: {self.msg}"
 
 
-def sign(
-    registry: str, img: str, secrets: SecretsMgr, transit: str
-) -> tuple[int, str, str]:
+def _get_signing_params(
+    registry: str, secrets: SecretsMgr, transit: str
+) -> tuple[str, str, str, str]:
+    """
+    Check preconditions and return (username, password, transit_mount, transit_key).
+
+    Raises SigningError if any prerequisite is missing.
+    """
     if not secrets.has_vault():
-        msg = "no vault configured, can't sign image"
-        logger.error(msg)
-        raise SigningError(msg)
+        raise SigningError("no vault configured, can't sign image")
 
     assert secrets.vault is not None
 
     if not secrets.has_transit_key(transit):
-        msg = f"vault transit key '{transit}' not found, can't sign image"
-        logger.error(msg)
-        raise SigningError(msg)
+        raise SigningError(f"vault transit key '{transit}' not found, can't sign image")
 
     try:
         _, username, password = secrets.registry_creds(registry)
     except SecretsMgrError as e:
-        msg = f"unable to obtain registry credentials for '{registry}': {e}"
-        logger.error(msg)
-        raise SigningError(msg) from e
+        raise SigningError(
+            f"unable to obtain registry credentials for '{registry}': {e}"
+        ) from e
 
     try:
         transit_mount, transit_key = secrets.transit(transit)
     except SecretsMgrError as e:
-        msg = f"unable to obtain transit key '{transit}': {e}"
-        logger.error(msg)
-        raise SigningError(msg) from e
+        raise SigningError(f"unable to obtain transit key '{transit}': {e}") from e
+
+    return username, password, transit_mount, transit_key
+
+
+def can_sign(registry: str, secrets: SecretsMgr, transit: str) -> bool:
+    try:
+        _get_signing_params(registry, secrets, transit)
+    except SigningError as e:
+        logger.debug(e.msg)
+        return False
+    else:
+        return True
+
+
+def sign(
+    registry: str, img: str, secrets: SecretsMgr, transit: str
+) -> tuple[int, str, str]:
+    username, password, transit_mount, transit_key = _get_signing_params(
+        registry, secrets, transit
+    )
 
     cmd: CmdArgs = [
         "cosign",
diff --git a/cbscore/src/cbscore/images/skopeo.py b/cbscore/src/cbscore/images/skopeo.py
index 511152df..a00064cd 100644
--- a/cbscore/src/cbscore/images/skopeo.py
+++ b/cbscore/src/cbscore/images/skopeo.py
@@ -24,7 +24,7 @@
 from cbscore.images import get_image_name
 from cbscore.images import logger as parent_logger
 from cbscore.images.errors import ImageNotFoundError, SkopeoError
-from cbscore.images.signing import sign
+from cbscore.images.signing import can_sign, sign
 from cbscore.utils import CmdArgs, Password, run_cmd
 from cbscore.utils.containers import get_container_image_base_uri
 from cbscore.utils.secrets import SecretsMgrError
@@ -99,20 +99,23 @@ def skopeo_copy(
 
     logger.info(f"copied '{src}' to '{dst}'")
 
-    try:
-        retcode, out, err = sign(dst_registry, dst, secrets, transit)
-    except SkopeoError as e:
-        logger.exception(f"error signing image '{dst}'")
-        raise e  # noqa: TRY201
+    if can_sign(dst_registry, secrets, transit):
+        try:
+            retcode, out, err = sign(dst_registry, dst, secrets, transit)
+        except SkopeoError as e:
+            logger.exception(f"error signing image '{dst}'")
+            raise e  # noqa: TRY201
 
-    if retcode != 0:
-        logger.error(f"error signing image '{dst}': {err}")
-        raise SkopeoError()
+        if retcode != 0:
+            logger.error(f"error signing image '{dst}': {err}")
+            raise SkopeoError()
 
-    logger.info(f"signed image '{dst}': {out}")
+        logger.info(f"signed image '{dst}': {out}")
+    else:
+        logger.warning(f"signing skipped for image '{dst}'")
 
 
-def skopeo_inspect(img: str, secrets: SecretsMgr) -> str:
+def skopeo_inspect(img: str, secrets: SecretsMgr, *, tls_verify: bool = True) -> str:
     logger.debug(f"inspect image '{img}'")
 
     try:
@@ -132,6 +135,7 @@ def skopeo_inspect(img: str, secrets: SecretsMgr) -> str:
         retcode, raw_out, err = skopeo(
             [
                 "inspect",
+                f"--tls-verify={tls_verify}",
                 "--creds",
                 Password(f"{user}:{passwd}"),
                 f"docker://{img}",
@@ -143,19 +147,22 @@ def skopeo_inspect(img: str, secrets: SecretsMgr) -> str:
 
     if retcode != 0:
         msg = f"error inspecting image '{img}': {err}"
-        logger.error(msg)
-        if re.match(r".*not\s+found.*", err):
+        if retcode == 2 or re.match(r".*not\s+found.*", err):
+            logger.debug(msg)
             raise ImageNotFoundError(img) from None
+        logger.error(msg)
         raise SkopeoError(msg) from None
 
     return raw_out
 
 
-def skopeo_image_exists(img: str, secrets: SecretsMgr) -> bool:
+def skopeo_image_exists(
+    img: str, secrets: SecretsMgr, *, tls_verify: bool = True
+) -> bool:
     logger.debug(f"check if image '{img}' exists")
 
     try:
-        _ = skopeo_inspect(img, secrets)
+        _ = skopeo_inspect(img, secrets, tls_verify=tls_verify)
     except ImageNotFoundError:
         logger.debug(f"image '{img}' does not exist")
         return False
diff --git a/cbscore/src/cbscore/runner.py b/cbscore/src/cbscore/runner.py
index 7e3318a1..c3029f85 100644
--- a/cbscore/src/cbscore/runner.py
+++ b/cbscore/src/cbscore/runner.py
@@ -118,6 +118,7 @@ async def runner(
     log_out_cb: AsyncRunCmdOutCallback | None = None,
     skip_build: bool = False,
     force: bool = False,
+    tls_verify: bool = True,
 ) -> None:
     our_actual_loc = Path(__file__).parent
 
@@ -174,6 +175,7 @@ async def runner(
     log to file:             {log_file_path if log_file_path else "not logging to file"}
     skip build:              {skip_build}
     force:                   {force}
+    tls-verify:              {tls_verify}
 """)
 
     if not entrypoint_path.exists() or not entrypoint_path.is_file():
@@ -250,7 +252,7 @@ async def runner(
         logger.error(msg)
         raise RunnerError(msg) from e
 
-    podman_args = ["--desc", desc_mount_loc]
+    podman_args = ["--desc", desc_mount_loc, f"--tls-verify={tls_verify}"]
     podman_volumes = {
         desc_file_path.resolve().as_posix(): desc_mount_loc,
         cbscore_path.resolve().as_posix(): "/runner/cbscore",