diff --git a/.sig/manifest.8E47A1EC35A1551D.asc b/.sig/manifest.8E47A1EC35A1551D.asc
index 0691eb1..b13eb80 100644
--- a/.sig/manifest.8E47A1EC35A1551D.asc
+++ b/.sig/manifest.8E47A1EC35A1551D.asc
@@ -1,16 +1,16 @@
 -----BEGIN PGP SIGNATURE-----
 
-iQIzBAABCgAdFiEEZ1U/vaRrtxq9LgsLjkeh7DWhVR0FAl+4nEwACgkQjkeh7DWh
-VR0HOg/+M33tcLn9pmiE+31ovH+4/XuDfYIuefWrxc/YLS+E8QIvmw5X+cXCuohV
-/qtfPg/EHddvMHq6BCMdo4XwqiPhYXbrh25FgT+bG2c8N8SMK797ffGo3DRH2ZbF
-yDFlQz0jShSbjvSFDFHYiS75ACKQ1AXN86gHr+/oH4aMiVtNA2AwrFmcajtY/nUN
-UmmRW6h/4mFbIp+MhbX9YH9Pc39da7ZvZyO/S6t9jA3M6Kwu5TZGkhPIHmuhnWc4
-CLG+PqQJabtYjt6VniJCcz4uubKKAgmjgB7RgVCQt05wLiB3Ca9MiTWZpGjuhedJ
-XrdphEep6cvWa4hvgWvKHQMtJEAKCD21rmnFXkGUl4hbe/joQ1rvEv+JL+QLIZv9
-S8rPeByVM4MtItJGIALL157K7dQdepxneRsGOJam6bI0ZLo3DJyDMODJWLFiHmUt
-WlZ2Queqp6UQbs19HJYgNve82wZsX/iXbqSRzg6V+043EDgOHpXX0zbJ6qMQXEd9
-UlJZQE4VPr/4V8LvYzMxbtlEClhAFIjKY2qAGwvkwoQgEcxYZ6fQZz6nriSPmWOO
-lFa5QQZEgJtMge9kQqmYAenD4J0F30S2Lj2IcS+t28XtTYyMiQ48cI37PUkuB5BC
-LSCx7lUGGLo5+Uz3aJ89yTpmhCXK0XvmCEqA0rPpz30NcWEaJ+Q=
-=7Skg
+iQIzBAABCgAdFiEEZ1U/vaRrtxq9LgsLjkeh7DWhVR0FAl+9voEACgkQjkeh7DWh
+VR1oSg//X/RqCuceOFQdn8HfC24P8mFuHgFFJpdcVDZALLrXek9QuBd++3VSQBPq
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+SKShEww86RLSj07jGfcgHjEXPQ5WZ5qmizsxJyXOITpR2wV1FmM=
+=jgfL
 -----END PGP SIGNATURE-----
diff --git a/.sig/manifest.txt b/.sig/manifest.txt
index 4fb7c0d..4e02fb8 100644
--- a/.sig/manifest.txt
+++ b/.sig/manifest.txt
@@ -1,8 +1,8 @@
 64263feac7b00952e9ec3b6c1fd11316faa58ff673c6bd085fac9f6f8d8389f6 .gitignore
 67377eee89dfc4411665474ac0bee0f9a19ea7e594bcc8606b0bc3ace69f0aa1 .gitlab-ci.yml
 ad3d473c630217dff7c4499efc1de46fc3a55068677c2bb3a21714aa56dd408a Makefile
-464ed12795e3e41eee83713709069fefb07f0676ba237894a9325aafe5c91e31 README.md
-3dfa934d88199ed8992d63d68bce81c5b82970b4a78d4ccde056d6039ee3cf5f sig
+7d6ada59fb41657c84b9fed7984a0e763d58c1fa851bf306db50f686eebdfbdd README.md
+e6517003db9161086c31e8fc21184273a1e66d536bf628739eae7118052c9be8 sig
 646a6c11ef22d51bd7fadff5ecc806d8d3e7c62151a0dd56bbeb59eca74c671c test/Dockerfile
 dd79ef0e6d0738321f916a5c85a60d44152fb1ffcd71572de98cf48e0d0d911c test/keys/user1.pub.asc
 c98a656738f188f650fa0107e3478d640c175a3db481a6c3cbc267f75a05b440 test/keys/user1.sec.asc
@@ -14,5 +14,5 @@ c0e3df63b1f01a83e17c463af9e37365a5e38ee0289d59cdfee725df202a311b test/keys/user3
 d4cbeffdbf7064aaffe94556b5879c88cddf479e3e76518f25c3491482abd789 test/keys/user4.sec.asc
 c608e63175a1e9cc3fe2500372769a9e30b808d2e4d4a950796d98dac14775ea test/keys/user5.pub.asc
 873f3a1e2da41587f4b5a0dad5d8b704a37144e54931fe3a167ea9648772a5dc test/keys/user5.sec.asc
-ab7f531be1e3f9075ee43e20dd230b6400cf856f7dfc857b848c5e9b766fc3f4 test/test.bats
+8a517fceb28c7afe5c6baba7792f5f914310800b7ddfde8d3265e26ab46cbee7 test/test.bats
 418903b58dad935ee3aa1dfcc4c4ac22fd77a838b87a5c2c3fe4e510a164f0a0 test/test_helper.bash
diff --git a/README.md b/README.md
index 51517e5..0084b86 100644
--- a/README.md
+++ b/README.md
@@ -52,7 +52,7 @@ The simple GPG signature toolchain for directories or git repos.
 
 ## Usage
 
-* sig verify [-g,--group=<group>] [-t,--threshold=<N>] [-m,--method=<git|detached> ]
+* sig verify [-g,--group=<group>] [-t,--threshold=<N>] [-m,--method=<git|detached> ] [-d,--diff=<branch>]
   * Verify m-of-n signatures by given group are present for directory
 * sig add
   * Add signature to manifest for this directory
@@ -119,7 +119,13 @@ sig verify --threshold 2
 #### Verify 3 unique signatures from specified signing group via Git method
 
 ```
-sig verify --threshold 2 --group myteam --method git
+sig verify --threshold 3 --group myteam --method git
+```
+
+#### Verify 2 unique signatures via detached method and diff on failure
+
+```
+sig verify --threshold 2 --diff master --method detached
 ```
 
 #### Add Detached Signature
diff --git a/sig b/sig
index fdca2e0..b8a027f 100755
--- a/sig
+++ b/sig
@@ -8,7 +8,7 @@ readonly MIN_GETOPT_VERSION=2.33
 
 ## Private Functions
 
-### Bail with error message
+### Exit with error message
 die() {
 	echo "$@" >&2
 	exit 1
@@ -117,7 +117,11 @@ check_tools(){
 ### Use git if available, else fall back to find
 get_files(){
 	if [ -d '.git' ] && command -v git >/dev/null; then
-		git ls-files | grep -v ".${PROGRAM}"
+		git ls-files \
+			--cached \
+			--others \
+			--exclude-standard \
+		| grep -v ".${PROGRAM}"
 	else
 		find . \
 			-type f \
@@ -233,27 +237,33 @@ verify_detached() {
 	for sig_filename in "${filename%.*}".*.asc; do
 		gpg --verify "${sig_filename}" "${filename}" >/dev/null 2>&1 || {
 			echo "Invalid detached signature: ${sig_filename}";
-			exit 1;
+			return 1;
 		}
 		file_fp=$( get_file_fp "${sig_filename}" )
 		fp=$( get_primary_fp "${file_fp}" )
 		uid=$( get_uid "${fp}" )
 
-		[[ "${seen_fps}" == *"${fp}"* ]] \
-			&& die "Duplicate signature: ${sig_filename}";
+		[[ "${seen_fps}" == *"${fp}"* ]] && {
+			echo "Duplicate signature: ${sig_filename}";
+			return 1;
+		}
 
 		echo "Verified detached signature by \"${uid}\""
 
 		if [ ! -z "${group}" ]; then
-			group_check_fp "${fp}" "${group}" \
-				|| die "Detached signing key not in group \"${group}\": ${fp}";
+			group_check_fp "${fp}" "${group}" || {
+				echo "Detached signing key not in group \"${group}\": ${fp}";
+				return 1;
+			}
 		fi
 
 		seen_fps="${seen_fps} ${fp}"
 		((sig_count=sig_count+1))
 	done
-	[[ "${sig_count}" -ge "${threshold}" ]] || \
-		die "Minimum detached signatures not found: ${sig_count}/${threshold}";
+	[[ "${sig_count}" -ge "${threshold}" ]] || {
+		echo "Minimum detached signatures not found: ${sig_count}/${threshold}";
+		return 1;
+	}
 }
 
 ### Verify all commits in git repo have valid signatures
@@ -263,7 +273,7 @@ verify_git(){
 	[ $# -eq 2 ] || die "Usage: verify_git <threshold> <group>"
 	local -r threshold="${1}"
 	local -r group="${2}"
-	local seen_fps="" sig_count=0 depth=0
+	local seen_fps="" sig_count=0 depth=0 ref commit fp uid
 
 	while [[ $depth != "$(git rev-list --count HEAD)" ]]; do
 		ref=HEAD~${depth}
@@ -271,8 +281,10 @@ verify_git(){
 		fp=$(git log --format="%GP" "$ref" -n1 )
 		uid=$( get_uid "${fp}" )
 
-		git verify-commit HEAD~${depth} >/dev/null 2>&1\
-			|| die "Unsigned commit: ${commit}"
+		git verify-commit HEAD~${depth} >/dev/null 2>&1 || {
+			echo "Unsigned commit: ${commit}";
+			return 1;
+		}
 
 		if [[ "${seen_fps}" != *"${fp}"* ]]; then
 			seen_fps="${seen_fps} ${fp}"
@@ -281,8 +293,10 @@ verify_git(){
 		fi
 
 		if [ ! -z "$group" ]; then
-			group_check_fp "${fp}" "${group}" \
-				|| die "Git signing key not in group \"${group}\": ${fp}"
+			group_check_fp "${fp}" "${group}" || {
+				echo "Git signing key not in group \"${group}\": ${fp}";
+				return 1;
+			}
 		fi
 
 		[[ "${sig_count}" -ge "${threshold}" ]] && break;
@@ -290,10 +304,75 @@ verify_git(){
 		((depth=depth+1))
 	done
 
-	[[ "${sig_count}" -ge "${threshold}" ]] \
-		|| die "Minimum git signatures not found: ${sig_count}/${threshold}";
+	[[ "${sig_count}" -ge "${threshold}" ]] || {
+		echo "Minimum git signatures not found: ${sig_count}/${threshold}";
+		return 1;
+	}
 }
 
+get_temp(){
+	echo "$(
+		mktemp \
+			--quiet \
+			--directory \
+			-t "$(basename "$0").XXXXXX" 2>/dev/null \
+		|| mktemp \
+			--quiet \
+			--directory
+	)"
+}
+
+verify_git_diff(){
+	[ $# -eq 4 ] \
+		|| die "Usage: verify_git_diff <ref> <threshold> <group> <method>"
+	command -v git >/dev/null 2>&1 \
+		|| die "Error: verify diff requires 'git' which is not installed"
+	local -r diff_ref=${1}
+	local -r threshold=${2}
+	local -r group=${3}
+	local -r method=${4}
+	local -r temp_repo=$(get_temp)
+	local -r git_root=$(git rev-parse --show-toplevel)
+	local -r curr_ref=$(git rev-parse HEAD)
+	set -x
+	cp -a "${git_root}/." "${temp_repo}/"
+	cd "${temp_repo}"
+	git reset --hard "${diff_ref}" >/dev/null 2>&1
+	if verify "${threshold}" "${group}" "${method}"; then
+		git --no-pager diff "${diff_ref}" "${curr_ref}"
+	else
+		echo "Verification of specifed diff ref failed: ${ref}"
+	fi
+	set +x
+}
+
+verify(){
+	[ $# -eq 3 ] || die "Usage: verify <threshold> <group> <method>"
+	local -r threshold=${1}
+	local -r group=${2}
+	local -r method=${3}
+	if [ -z "$method" ] || [ "$method" == "git" ]; then
+		if [ "$method" == "git" ]; then
+			command -v git >/dev/null 2>&1 \
+			|| die "Error: method 'git' specified and git is not installed"
+		fi
+		if command -v git >/dev/null 2>&1 \
+			&& ( [ -d .git ] || git rev-parse --git-dir > /dev/null 2>&1 );
+		then
+			verify_git "${threshold}" "${group}" || return 1
+		fi
+	fi
+
+	if [ -z "$method" ] || [ "$method" == "detached" ]; then
+		( [ -d ".${PROGRAM}" ] && ls ."${PROGRAM}"/*.asc >/dev/null 2>&1 ) || {
+			echo "Error: No signatures";
+			return 1;
+		}
+		cmd_manifest || return 1
+		verify_detached "${threshold}" "${group}" ."${PROGRAM}"/manifest.txt \
+			|| return 1
+	fi
+}
 
 ## Public Commands
 
@@ -306,32 +385,26 @@ cmd_manifest() {
 }
 
 cmd_verify() {
-	local opts threshold=1 group="" method=""
-	opts="$(getopt -o t:g:m: -l threshold:,group:,method: -n "$PROGRAM" -- "$@")"
+	local opts threshold=1 group="" method="" diff=""
+	local -r args="$@"
+	opts="$(getopt -o t:g:m:d: -l threshold:,group:,method:,diff: -n "$PROGRAM" -- "$@")"
 	eval set -- "$opts"
 	while true; do case $1 in
 		-t|--threshold) threshold="$2"; shift 2 ;;
 		-g|--group) group="$2"; shift 2 ;;
 		-m|--method) method="$2"; shift 2 ;;
+		-d|--diff) diff="$2"; shift 2 ;;
 		--) shift; break ;;
 	esac done
 
-	if [ -z "$method" ] || [ "$method" == "git" ]; then
-		if [ "$method" == "git" ]; then
-			command -v git >/dev/null 2>&1 \
-			|| die "Error: method 'git' specified and git is not installed"
-		fi
-		command -v git >/dev/null 2>&1 \
-			&& ( [ -d .git ] || git rev-parse --git-dir > /dev/null 2>&1 ) \
-			&& verify_git "${threshold}" "${group}"
-	fi
-
-	if [ -z "$method" ] || [ "$method" == "detached" ]; then
-		( [ -d ".${PROGRAM}" ] && ls ."${PROGRAM}"/*.asc >/dev/null 2>&1 ) \
-			|| die "Error: No signatures"
-		cmd_manifest
-		verify_detached "${threshold}" "${group}" ."${PROGRAM}"/manifest.txt
+	if verify "$threshold" "$group" "$method"; then
+		return 0
+	elif [ ! -z "$diff" ]; then
+		echo "Verification failed."
+		echo "Attempting verified diff against git ref ${diff} ..."
+		verify_git_diff "$diff" "$threshold" "$group" "$method"
 	fi
+	return 1
 }
 
 cmd_fetch() {
@@ -405,8 +478,8 @@ cmd_usage() {
 	Usage:
 	    $PROGRAM add
 	        Add signature to manifest for this directory
-	    $PROGRAM verify [-g,--group=<group>] [-t,--threshold=<N>] [-m,--method=<git|detached> ]
-	        Verify m-of-n signatures by given group are present for directory
+	    $PROGRAM verify [-g,--group=<group>] [-t,--threshold=<N>] [-m,--method=<git|detached> ] [d,--diff=<branch>]
+	        Verify m-of-n signatures by given group are present for directory.
 	    $PROGRAM fetch [-g,--group=<group>]
 	    	Fetch key by fingerprint. Optionally add to group.
 	    $PROGRAM manifest
diff --git a/test/test.bats b/test/test.bats
index d3139e5..23c788c 100644
--- a/test/test.bats
+++ b/test/test.bats
@@ -197,3 +197,29 @@ load test_helper
 	run sig verify --method detached --threshold 2 --group maintainers
 	[ "$status" -eq 1 ]
 }
+
+@test "Verify diff shows changes between feature branch and verified master" {
+	git init
+
+	set_identity "user1"
+	echo "test string" > testfile
+	sig add
+	git add .
+	git commit -m "User 1 Commit"
+
+	set_identity "user2"
+	sig add
+	git add .
+	git commit -m "User 2 Commit"
+
+	set_identity "user1"
+	git checkout -b feature_branch
+	echo "updated test string" > somefile1
+	sig add
+	git add .
+	git commit -m "User 1 Update Commit"
+
+	run sig verify --diff master --method detached --threshold 2
+	[ "$status" -eq 1 ]
+	echo "${output}" | grep "updated test string"
+}