diff --git a/.env.load.example b/.env.load.example
index 385e82e..0070935 100644
--- a/.env.load.example
+++ b/.env.load.example
@@ -67,3 +67,16 @@ OBSERVABILITY_EVALUATION_INTERVAL=1s
 OBSERVABILITY_TIMEOUT_SECONDS=90
 OBSERVABILITY_GRAFANA_ADMIN_USER=local-admin
 OBSERVABILITY_GRAFANA_ADMIN_PASSWORD=GENERATE_OBSERVABILITY_GRAFANA_ADMIN_PASSWORD
+
+# The encrypted backup drill keeps its MinIO API and console on dynamically
+# allocated loopback ports. Secrets are generated only in ignored .env.load.
+BACKUP_MINIO_API_PORT=0
+BACKUP_MINIO_CONSOLE_PORT=0
+BACKUP_MINIO_ROOT_USER=GENERATE_BACKUP_MINIO_ROOT_USER
+BACKUP_MINIO_ROOT_PASSWORD=GENERATE_BACKUP_MINIO_ROOT_PASSWORD
+BACKUP_RESTIC_PASSWORD=GENERATE_BACKUP_RESTIC_PASSWORD
+BACKUP_BUCKET_PREFIX=wnh-backup
+BACKUP_TIMEOUT_SECONDS=120
+BACKUP_INTERRUPTION_CHUNKS=300
+BACKUP_INTERRUPTION_CHUNK_BYTES=1048576
+BACKUP_INTERRUPTION_INTERVAL_SECONDS=0.1
diff --git a/Dockerfile.backup b/Dockerfile.backup
new file mode 100644
index 0000000..1cb0019
--- /dev/null
+++ b/Dockerfile.backup
@@ -0,0 +1,20 @@
+FROM golang:1.26.5-alpine3.23@sha256:622e56dbc11a8cfe87cafa2331e9a201877271cbff918af53d3be315f3da88cc AS restic
+
+RUN CGO_ENABLED=0 go install github.com/restic/restic/cmd/restic@v0.19.1
+
+FROM alpine:3.23.3@sha256:25109184c71bdad752c8312a8623239686a9a2071e8825f20acb8f2198c3f659
+
+RUN apk add --no-cache \
+      ca-certificates=20260611-r0 \
+      libcrypto3=3.5.7-r0 \
+      libssl3=3.5.7-r0 \
+      musl=1.2.5-r23 \
+      musl-utils=1.2.5-r23 \
+      postgresql18-client=18.4-r0 \
+      zlib=1.3.2-r0
+
+COPY --from=restic /go/bin/restic /usr/local/bin/restic
+
+ENTRYPOINT []
+USER 10001:10001
+CMD ["restic", "version"]
diff --git a/Dockerfile.minio b/Dockerfile.minio
new file mode 100644
index 0000000..ffe4827
--- /dev/null
+++ b/Dockerfile.minio
@@ -0,0 +1,81 @@
+FROM golang:1.26.5-alpine3.23@sha256:622e56dbc11a8cfe87cafa2331e9a201877271cbff918af53d3be315f3da88cc AS minio_builder
+
+ADD --checksum=sha256:45521908307306e925c98d629e1c17d78c8b72b6ee242b1bfb1409f7d8ee5841 \
+  https://github.com/minio/minio/archive/9e49d5e7a648f00e26f2246f4dc28e6b07f8c84a.tar.gz \
+  /tmp/minio.tar.gz
+
+WORKDIR /src
+
+RUN tar --extract --gzip --file /tmp/minio.tar.gz \
+    --directory . --strip-components=1 \
+  && go get \
+    github.com/apache/thrift@v0.23.0 \
+    github.com/buger/jsonparser@v1.1.2 \
+    github.com/prometheus/prometheus@v0.311.3 \
+    golang.org/x/crypto@v0.52.0 \
+    golang.org/x/net@v0.55.0 \
+    google.golang.org/grpc@v1.81.1 \
+  && CGO_ENABLED=0 go build \
+    -mod=mod \
+    -trimpath \
+    -tags kqueue \
+    -ldflags="-s -w \
+      -X github.com/minio/minio/cmd.Version=2025-10-15T17:29:55Z \
+      -X github.com/minio/minio/cmd.CopyrightYear=2025 \
+      -X github.com/minio/minio/cmd.ReleaseTag=RELEASE.2025-10-15T17-29-55Z \
+      -X github.com/minio/minio/cmd.CommitID=9e49d5e7a648f00e26f2246f4dc28e6b07f8c84a \
+      -X github.com/minio/minio/cmd.ShortCommitID=9e49d5e7a648" \
+    -o /out/minio .
+
+FROM golang:1.26.5-alpine3.23@sha256:622e56dbc11a8cfe87cafa2331e9a201877271cbff918af53d3be315f3da88cc AS mc_builder
+
+ADD --checksum=sha256:95cd293c7119f16921a6dc515a1fb74a2227f19fd994b9c8b770a154e802ac44 \
+  https://github.com/minio/mc/archive/7394ce0dd2a80935aded936b09fa12cbb3cb8096.tar.gz \
+  /tmp/mc.tar.gz
+
+WORKDIR /src
+
+RUN tar --extract --gzip --file /tmp/mc.tar.gz \
+    --directory . --strip-components=1 \
+  && go get \
+    github.com/prometheus/prometheus@v0.311.3 \
+    golang.org/x/crypto@v0.52.0 \
+    golang.org/x/net@v0.55.0 \
+    google.golang.org/grpc@v1.81.1 \
+  && go mod tidy \
+  && CGO_ENABLED=0 go build \
+    -trimpath \
+    -tags kqueue \
+    -ldflags="-s -w \
+      -X github.com/minio/mc/cmd.Version=2025-08-13T08:35:41Z \
+      -X github.com/minio/mc/cmd.CopyrightYear=2025 \
+      -X github.com/minio/mc/cmd.ReleaseTag=RELEASE.2025-08-13T08-35-41Z \
+      -X github.com/minio/mc/cmd.CommitID=7394ce0dd2a80935aded936b09fa12cbb3cb8096 \
+      -X github.com/minio/mc/cmd.ShortCommitID=7394ce0dd2a8" \
+    -o /out/mc .
+
+FROM alpine:3.23.3@sha256:25109184c71bdad752c8312a8623239686a9a2071e8825f20acb8f2198c3f659 AS runtime
+
+RUN apk add --no-cache \
+      ca-certificates=20260611-r0 \
+      libcrypto3=3.5.7-r0 \
+      libssl3=3.5.7-r0 \
+      musl=1.2.5-r23 \
+      musl-utils=1.2.5-r23 \
+      zlib=1.3.2-r0
+
+USER 10001:10001
+
+FROM runtime AS server
+
+COPY --from=minio_builder /out/minio /usr/local/bin/minio
+
+ENTRYPOINT ["minio"]
+CMD ["--version"]
+
+FROM runtime AS client
+
+COPY --from=mc_builder /out/mc /usr/local/bin/mc
+
+ENTRYPOINT ["mc"]
+CMD ["--version"]
diff --git a/README.md b/README.md
index 3e1e993..4cb5057 100644
--- a/README.md
+++ b/README.md
@@ -92,6 +92,20 @@ backup_path=$(printf '%s\n' "$backup_output" | sed -n 's/^Backup: //p')
 ./scripts/restore-drill-compose.sh "$backup_path"
 ```
 
+For the reproducible encrypted S3-compatible drill, first start the isolated
+load project and then run:
+
+```bash
+./scripts/load-stack-up.sh
+./scripts/backup-s3-drill.sh local-encrypted-backup
+```
+
+The command generates MinIO and Restic secrets only in ignored mode-`0600`
+`.env.load`, streams `pg_dump` directly into an encrypted Restic repository,
+restores it into a new temporary database, checks corruption and interruption
+failure paths, removes those temporary buckets, and retains the successful
+encrypted bucket in local MinIO. It never writes a plaintext dump to the host.
+
 The commands, boundaries, and unclaimed production properties are documented
 in [the operations runbook](docs/operations.md).
 
@@ -151,10 +165,11 @@ an isolated PostgreSQL volume:
 It checks shell scripts, Dockerfiles, the GitHub Actions workflow, every Compose
 profile, the rendered Helm chart, tracked-source secrets and infrastructure
 misconfigurations, Elixir formatting/compilation/xref/Credo/Sobelow/Dialyzer,
-retired Hex packages, locked npm dependencies, all Phoenix tests, and the
-production release image. Its generated database credentials are random and
-exist only for that run. The exact database volume, networks, temporary source
-snapshot, and one-run images are removed automatically.
+retired Hex packages, locked npm dependencies, all Phoenix tests, the pinned
+backup-tool, MinIO server/client, and production release images. Its generated
+database credentials are random and exist only for that run. The exact database
+volume, networks, temporary source snapshot, and one-run images are removed
+automatically.
 
 The cursor-pagination database benchmark also creates a one-run Compose
 project, random database credentials, and a separate PostgreSQL volume:
diff --git a/compose.backup.yaml b/compose.backup.yaml
new file mode 100644
index 0000000..f94e472
--- /dev/null
+++ b/compose.backup.yaml
@@ -0,0 +1,118 @@
+services:
+  minio-permissions:
+    image: who-need-help:minio-local
+    build:
+      context: .
+      dockerfile: Dockerfile.minio
+      target: server
+    entrypoint: ["/bin/sh", "-euc"]
+    command:
+      - chown -R 10001:10001 /data
+    volumes:
+      - minio_data:/data
+    user: "0:0"
+    read_only: true
+    cap_drop: [ALL]
+    cap_add: [CHOWN]
+    security_opt:
+      - no-new-privileges:true
+    networks: [internal]
+    restart: "no"
+    profiles: [backup]
+
+  minio:
+    image: who-need-help:minio-local
+    build:
+      context: .
+      dockerfile: Dockerfile.minio
+      target: server
+    command: ["server", "/data", "--console-address", ":9001"]
+    environment:
+      MINIO_ROOT_USER: ${BACKUP_MINIO_ROOT_USER:?Set BACKUP_MINIO_ROOT_USER}
+      MINIO_ROOT_PASSWORD: ${BACKUP_MINIO_ROOT_PASSWORD:?Set BACKUP_MINIO_ROOT_PASSWORD}
+    volumes:
+      - minio_data:/data
+    ports:
+      - target: 9000
+        published: "${BACKUP_MINIO_API_PORT:-0}"
+        host_ip: 127.0.0.1
+        protocol: tcp
+      - target: 9001
+        published: "${BACKUP_MINIO_CONSOLE_PORT:-0}"
+        host_ip: 127.0.0.1
+        protocol: tcp
+    healthcheck:
+      test: ["CMD", "wget", "--quiet", "--spider", "http://127.0.0.1:9000/minio/health/ready"]
+      interval: 2s
+      timeout: 3s
+      retries: 30
+    depends_on:
+      minio-permissions:
+        condition: service_completed_successfully
+    user: "10001:10001"
+    read_only: true
+    tmpfs:
+      - /tmp
+    cap_drop: [ALL]
+    security_opt:
+      - no-new-privileges:true
+    networks: [internal, backup_host]
+    restart: unless-stopped
+    profiles: [backup]
+
+  minio-client:
+    image: who-need-help:mc-local
+    build:
+      context: .
+      dockerfile: Dockerfile.minio
+      target: client
+    entrypoint: ["mc"]
+    command: ["--version"]
+    environment:
+      MC_CONFIG_DIR: /tmp/mc
+      MC_HOST_local: http://${BACKUP_MINIO_ROOT_USER:?Set BACKUP_MINIO_ROOT_USER}:${BACKUP_MINIO_ROOT_PASSWORD:?Set BACKUP_MINIO_ROOT_PASSWORD}@minio:9000
+    volumes:
+      - ${BACKUP_RUNTIME_DIR:?Set BACKUP_RUNTIME_DIR for the backup profile}:/work
+    user: "${BACKUP_HOST_UID:?Set BACKUP_HOST_UID}:${BACKUP_HOST_GID:?Set BACKUP_HOST_GID}"
+    read_only: true
+    tmpfs:
+      - /tmp
+    cap_drop: [ALL]
+    security_opt:
+      - no-new-privileges:true
+    networks: [internal]
+    profiles: [backup]
+
+  backup-tools:
+    image: who-need-help:backup-tools
+    build:
+      context: .
+      dockerfile: Dockerfile.backup
+    environment:
+      PGHOST: db
+      PGPORT: "5432"
+      PGUSER: ${POSTGRES_USER:?Set POSTGRES_USER}
+      PGPASSWORD: ${POSTGRES_PASSWORD:?Set POSTGRES_PASSWORD}
+      PGDATABASE: ${POSTGRES_DB:?Set POSTGRES_DB}
+      AWS_ACCESS_KEY_ID: ${BACKUP_MINIO_ROOT_USER:?Set BACKUP_MINIO_ROOT_USER}
+      AWS_SECRET_ACCESS_KEY: ${BACKUP_MINIO_ROOT_PASSWORD:?Set BACKUP_MINIO_ROOT_PASSWORD}
+      RESTIC_PASSWORD: ${BACKUP_RESTIC_PASSWORD:?Set BACKUP_RESTIC_PASSWORD}
+      RESTIC_CACHE_DIR: /tmp/restic-cache
+      BACKUP_INTERRUPTION_CHUNKS: ${BACKUP_INTERRUPTION_CHUNKS:?Set BACKUP_INTERRUPTION_CHUNKS}
+      BACKUP_INTERRUPTION_CHUNK_BYTES: ${BACKUP_INTERRUPTION_CHUNK_BYTES:?Set BACKUP_INTERRUPTION_CHUNK_BYTES}
+      BACKUP_INTERRUPTION_INTERVAL_SECONDS: ${BACKUP_INTERRUPTION_INTERVAL_SECONDS:?Set BACKUP_INTERRUPTION_INTERVAL_SECONDS}
+    user: "10001:10001"
+    read_only: true
+    tmpfs:
+      - /tmp
+    cap_drop: [ALL]
+    security_opt:
+      - no-new-privileges:true
+    networks: [internal]
+    profiles: [backup]
+
+networks:
+  backup_host:
+
+volumes:
+  minio_data:
diff --git a/docs/dependency-baseline.md b/docs/dependency-baseline.md
index 383318a..a7e4b2f 100644
--- a/docs/dependency-baseline.md
+++ b/docs/dependency-baseline.md
@@ -42,6 +42,10 @@ package checksums are in `mix.lock` and `assets/package-lock.json`.
 | Alertmanager | 0.33.1 |
 | Grafana | 13.1.0 |
 | Python alert-boundary runtime | 3.14.6 / Alpine 3.23 |
+| Restic | 0.19.1, rebuilt with Go 1.26.5 |
+| MinIO server | RELEASE.2025-10-15T17-29-55Z, rebuilt with Go 1.26.5 |
+| MinIO client | RELEASE.2025-08-13T08-35-41Z, rebuilt with Go 1.26.5 |
+| Backup runtime | Alpine 3.23.3 / PostgreSQL client 18.4-r0 |
 | Debian builder/runner snapshot | trixie-20260713-slim |
 
 Every external Compose/kind service image and every Dockerfile base image is
@@ -49,6 +53,15 @@ locked to both an exact tag and an OCI digest. The observed local Docker tooling
 was Docker Engine/CLI 29.6.2, Compose 5.3.1, and Buildx 0.35.0; their official
 release feeds reported those same versions as current during verification.
 
+`Dockerfile.minio` fetches checksum-pinned upstream source commits for MinIO
+server and client and records every dependency override used to rebuild them.
+The current overrides move Apache Thrift, jsonparser, Prometheus, Go crypto/net,
+and gRPC dependencies to the versions checked by the image security gate.
+Both projects are AGPLv3; anyone distributing or operating modified builds must
+review and satisfy the applicable license obligations. This repository keeps
+the exact upstream source identifiers and the complete modification/build
+recipe; this statement is operational documentation, not legal advice.
+
 ## Android and local Kubernetes
 
 | Component | Locked version |
@@ -106,6 +119,10 @@ Credo, Dialyxir, and Sobelow are locked in `mix.lock`.
 - [Alertmanager releases](https://github.com/prometheus/alertmanager/releases)
 - [Grafana releases](https://github.com/grafana/grafana/releases)
 - [Python releases](https://www.python.org/downloads/)
+- [Go release history](https://go.dev/doc/devel/release)
+- [Restic releases](https://github.com/restic/restic/releases)
+- [MinIO releases](https://github.com/minio/minio/releases)
+- [MinIO client releases](https://github.com/minio/mc/releases)
 - [Android Gradle Plugin 9.3.0 release notes](https://developer.android.com/build/releases/agp-9-3-0-release-notes)
 - [Android 17 SDK setup](https://developer.android.com/about/versions/17/setup-sdk)
 - [Build instrumented tests](https://developer.android.com/training/testing/instrumented-tests)
@@ -136,4 +153,5 @@ docker run --rm who-need-help:node-deps npm outdated --json
 ./scripts/android-build.sh
 ./scripts/android-instrumentation-test.sh
 ./scripts/observability-run.sh local-observability
+./scripts/backup-s3-drill.sh local-encrypted-backup
 ```
diff --git a/docs/local-hardening-plan.md b/docs/local-hardening-plan.md
index 7991c34..60e3975 100644
--- a/docs/local-hardening-plan.md
+++ b/docs/local-hardening-plan.md
@@ -14,7 +14,7 @@ item below unless the evidence column explicitly describes a local mock.
 | Database scale | Core discovery/chat/moderation lists call unbounded `Repo.all()` | Cursor-bounded queries pass behavior tests and measured `EXPLAIN ANALYZE` checks on an isolated generated dataset |
 | Load and resilience | Public/readiness/heartbeat k6 profile exists | Authenticated writes, chat, tracking, reconnect, rolling replacement, and worker retry profiles pass without touching staging data |
 | Observability | Completed locally: protected per-process metrics feed a pinned Prometheus/Grafana/Alertmanager profile | All 3 direct web targets are up before/after the drill; a verified replica stop delivers firing and resolved webhooks; Grafana datasource/dashboard and an empty DB-count diff are retained |
-| Backup | Validated local custom-format dump and restore drill exist | An encrypted artifact is uploaded to local S3-compatible MinIO and restored into a fresh database; corruption and interrupted-upload checks fail closed |
+| Backup | Completed locally: a plaintext-free Restic stream is retained in pinned local MinIO | The encrypted repository passes full-data checking and fresh-database restore; corrupted configuration and an interrupted upload fail closed, leave no snapshot, and their temporary buckets are removed |
 | External boundaries | Mailpit and a fake GitHub strategy cover parts of SMTP/OAuth | Local protocol-level SMTP/OAuth mocks and the applicable push adapter boundary cover success, rejection, retry, replay, and timeout |
 | Final regression | 163 Phoenix tests plus reproducible browser and Android device suites | Browser, Android, API, DB, WebSocket, backup, monitoring, failure, cleanup, docs, and clean Git are verified from the final commits |
 
@@ -94,5 +94,12 @@ The goal remains open while any row lacks reproducible local evidence.
   dashboard, and routes the `up == 0` rule through Alertmanager. The canonical
   drill observed both firing and resolved webhooks for the exact stopped
   replica, restored all three targets, and left database counts unchanged.
+- The encrypted backup profile streams PostgreSQL custom format through Restic
+  directly into local MinIO without a host plaintext archive. The canonical
+  drill restored 23 public tables with all 10 migrations and PostGIS 3.6.4,
+  rejected an intentionally corrupted repository, stopped a scoped upload
+  after an encrypted object reached MinIO, published no interrupted snapshot,
+  pruned the unreferenced packs, removed both temporary buckets and the
+  temporary restore database, and left source table counts unchanged.
 - The remaining rows above are still pending; this document is not a
   completion claim for the entire hardening goal.
diff --git a/docs/operations.md b/docs/operations.md
index 2ce0a7b..73e1a64 100644
--- a/docs/operations.md
+++ b/docs/operations.md
@@ -26,6 +26,62 @@ globals such as roles and tablespaces are not part of `pg_dump`; deployment
 credentials and database roles must be provisioned separately from secrets.
 Local backup files on the same workstation are not an off-site backup.
 
+## Encrypted local S3-compatible backup drill
+
+The isolated load project can run a complete encrypted Restic/MinIO drill:
+
+```bash
+./scripts/load-stack-up.sh
+./scripts/backup-s3-drill.sh local-encrypted-backup
+```
+
+The script refuses the staging Compose project and validates the project and
+service labels of every pre-existing container in its scope. On first use,
+`scripts/ensure-local-load-env.sh` generates independent random MinIO and
+Restic credentials in ignored `.env.load` and restricts that file to mode
+`0600`. MinIO publishes Docker-assigned ports only on `127.0.0.1`; the observed
+API and console URLs are printed after a successful run.
+
+The backup tool combines the matching PostgreSQL 18 client with pinned Restic
+rebuilt on Go 1.26.5. MinIO server and client are also rebuilt as non-root
+Alpine images from checksum-pinned upstream source commits with the exact
+dependency updates recorded in `Dockerfile.minio`. The quality gate verifies
+their reported release, commit, Go runtime, configured user, and current
+HIGH/CRITICAL vulnerability scan. `restic backup --stdin-from-command` runs a
+custom-format `pg_dump`, checks the producer exit status, encrypts the data,
+and uploads it directly to MinIO. No plaintext database dump is written to the
+host. The drill then:
+
+1. runs `restic check --read-data`;
+2. streams `restic dump` into `pg_restore --list`;
+3. restores into a uniquely named database created from `template0`;
+4. checks tables, current Ecto migrations, PostGIS, and release migration
+   readiness before removing that exact database;
+5. clones and corrupts an isolated repository and requires both check and dump
+   to fail;
+6. stops an exact scoped in-progress backup container only after encrypted
+   objects reach MinIO, requires zero published snapshots, prunes unreferenced
+   packs, and rechecks the repository;
+7. removes and verifies removal of the corruption/interruption buckets and
+   requires source table counts to remain unchanged.
+
+The successful encrypted bucket is deliberately retained in the named local
+MinIO volume. Non-secret evidence is written under ignored
+`output/backups-s3/<run-label>/`; the runtime scratch directory is under
+ignored `tmp/backup-s3/`. Use a unique lowercase run label of at most 32
+characters. The command refuses to replace an existing retained bucket.
+
+MinIO server and client are AGPLv3. `Dockerfile.minio` identifies the exact
+upstream source commits and contains the dependency changes and complete build
+commands used here. Before distributing or publicly operating modified images,
+review the license and make the corresponding source available as required;
+this runbook does not provide legal advice.
+
+This verifies encryption, local S3 protocol use, restore mechanics, and two
+failure paths on the observed workstation. A MinIO volume on that same
+workstation is not an off-site backup and does not establish production RPO,
+RTO, retention, capacity, key custody, object locking, or database HA.
+
 ## Isolated restore drill
 
 Run a real restore into a uniquely named temporary database:
diff --git a/docs/verification.md b/docs/verification.md
index 1316790..ff56118 100644
--- a/docs/verification.md
+++ b/docs/verification.md
@@ -21,6 +21,7 @@ results from product limits and unknown production properties.
 | Android client | Local and public-staging clients implemented and emulator-verified | The native packages `org.whoneedhelp.mobile.debug` and `org.whoneedhelp.mobile.staging` launch the same authenticated LiveView app. Public HTTPS login, map, two-way chat, permission prompts, minimized foreground-service location updates, notification Stop, deep-link routing, and server cleanup were exercised on API 37. | Production signing, Play Store publication, verified Android App Links, unattended/background-permission tracking, and iOS are not implemented. |
 | Multiple web/worker instances | Implemented and locally failure/rollout-verified | The isolated Compose profile passed BEAM crashes and sequential replacement with 3 web/2 worker replicas, all five nodes joined, PubSub passed, and 743/743 readiness requests succeeded. The project-owned kind cluster replaced all 2 web/2 worker pod UIDs under `maxUnavailable=0`; all four replacement pods joined and PubSub passed. | Local PostGIS is a single instance. Production database HA, backups, and recovery are operator work and are not claimed complete. |
 | Local observability | Implemented and protocol-verified | Pinned Prometheus scraped all 3 direct load web targets with a file Bearer credential; Grafana provisioned a healthy datasource and four-panel dashboard; Alertmanager delivered firing and resolved webhooks for an induced scoped replica stop. | Local delivery does not establish production retention, notification-provider reliability, on-call policy, or measured alert thresholds. |
+| Encrypted local backup | Implemented and failure-verified | Pinned Restic streamed PostgreSQL custom format into pinned local MinIO with no host plaintext dump, passed full-data checking and a fresh-database restore, rejected a corrupted repository, and published no snapshot for an interrupted upload. | The retained MinIO volume is on the same workstation; this is not off-site storage, database HA, or a production RPO/RTO/retention claim. |
 
 ## Reproducible checks
 
@@ -31,12 +32,15 @@ results from product limits and unknown production properties.
 - `mix compile --force --warnings-as-errors` and
   `mix format --check-formatted`: passed against the same final source.
 - `./scripts/quality.sh` passed ShellCheck 0.11.0, Hadolint 2.14.0 at warning
-  threshold, actionlint 1.7.12, all five Compose renders, Helm lint, Trivy
+  threshold, actionlint 1.7.12, all six Compose renders, Helm lint, Trivy
   source/rendered-manifest scanning, xref, Credo high-priority checks, Sobelow
   strict/private checks, Hex audit, 163 Phoenix tests, both npm audits, and the
-  production-image vulnerability scan. The rendered Helm manifest and Debian
-  13.6 release image each reported zero HIGH/CRITICAL findings under the
-  configured gates.
+  backup/MinIO/mc/release-image vulnerability scans. The rendered Helm manifest
+  reported zero HIGH/CRITICAL misconfigurations; the Alpine backup, MinIO, and
+  mc images and the Debian 13.6 release image each reported zero HIGH/CRITICAL
+  vulnerabilities under the configured gates. The backup binary reported
+  Restic 0.19.1 compiled with Go 1.26.5; MinIO and mc reported their pinned
+  commits and Go 1.26.5.
 - Dialyzer passed with three path- and warning-specific documented filters and
   zero unused filters. Two findings are opaque-type warnings at Ecto
   `Multi`/`MapSet` call sites; the third is the generated Gettext backend's
@@ -90,6 +94,19 @@ results from product limits and unknown production properties.
   running, and the checked user/request/message counts were identical before
   and after. A subsequent full drill returned all monitoring services to
   healthy.
+- The encrypted S3 canonical drill restored 23 public application tables, all
+  10 current migrations, 14 categories, and PostGIS 3.6.4 into a fresh
+  temporary database. `restic check --read-data` passed for the retained
+  repository. Flipping the first byte of an isolated cloned repository made
+  both `check` and `dump` exit nonzero. Stopping the exact backup container
+  after uploaded encrypted objects produced exit 130 and zero snapshots;
+  Restic identified and pruned 32.809 MiB of unreferenced packs, then passed a
+  second full-data check. Only the retained canonical bucket remained, the
+  restore database and interruption container were absent, no configured
+  secret appeared in retained evidence, and the source database count diff was
+  empty. The obsolete successful-run bucket was then removed; only the final
+  canonical bucket remains. Evidence is retained at
+  `output/backups-s3/backup-canonical-20260719d`.
 - The committed browser suite passed its 1/1 bootstrap and all 8/8 Chromium
   specs against a fresh PostGIS volume with two web and two worker replicas on
   2026-07-19. The retained successful-run artifact directory is
diff --git a/scripts/backup-s3-drill.sh b/scripts/backup-s3-drill.sh
new file mode 100755
index 0000000..249223a
--- /dev/null
+++ b/scripts/backup-s3-drill.sh
@@ -0,0 +1,631 @@
+#!/usr/bin/env bash
+set -euo pipefail
+umask 077
+
+ROOT=$(CDPATH='' cd -- "$(dirname -- "$0")/.." && pwd)
+ENV_FILE="$ROOT/.env.load"
+LABEL=${1:-"backup-$(date -u +%Y%m%d%H%M%S)"}
+
+if [[ ! -f "$ENV_FILE" ]]; then
+  echo "Missing $ENV_FILE. Run scripts/ensure-local-load-env.sh first." >&2
+  exit 1
+fi
+
+set -a
+# shellcheck source=/dev/null
+. "$ENV_FILE"
+set +a
+
+for name in LOAD_PROJECT POSTGRES_DB POSTGRES_USER POSTGRES_PASSWORD DATABASE_URL \
+  BACKUP_MINIO_API_PORT BACKUP_MINIO_CONSOLE_PORT BACKUP_MINIO_ROOT_USER \
+  BACKUP_MINIO_ROOT_PASSWORD BACKUP_RESTIC_PASSWORD BACKUP_BUCKET_PREFIX \
+  BACKUP_TIMEOUT_SECONDS BACKUP_INTERRUPTION_CHUNKS \
+  BACKUP_INTERRUPTION_CHUNK_BYTES BACKUP_INTERRUPTION_INTERVAL_SECONDS; do
+  if [[ -z "${!name:-}" ]]; then
+    echo "$name is missing from .env.load" >&2
+    exit 1
+  fi
+done
+
+if [[ "$LOAD_PROJECT" == "who_need_help" ]]; then
+  echo "The encrypted backup drill must not use the staging Compose project." >&2
+  exit 1
+fi
+
+if [[ ! "$LABEL" =~ ^[a-z0-9][a-z0-9-]{0,31}$ ]]; then
+  echo "Run label must be 1-32 lowercase letters, numbers, or dashes." >&2
+  exit 1
+fi
+
+if [[ ! "$BACKUP_BUCKET_PREFIX" =~ ^[a-z0-9][a-z0-9-]{1,19}$ ]]; then
+  echo "BACKUP_BUCKET_PREFIX must be 2-20 lowercase letters, numbers, or dashes." >&2
+  exit 1
+fi
+
+for name in BACKUP_MINIO_API_PORT BACKUP_MINIO_CONSOLE_PORT; do
+  if [[ ! "${!name}" =~ ^[0-9]+$ ]] || ((10#${!name} > 65535)); then
+    echo "$name must be a TCP port number from 0 through 65535." >&2
+    exit 1
+  fi
+done
+
+for name in BACKUP_TIMEOUT_SECONDS BACKUP_INTERRUPTION_CHUNKS \
+  BACKUP_INTERRUPTION_CHUNK_BYTES; do
+  if [[ ! "${!name}" =~ ^[1-9][0-9]*$ ]]; then
+    echo "$name must be a positive integer." >&2
+    exit 1
+  fi
+done
+
+if ! awk -v value="$BACKUP_INTERRUPTION_INTERVAL_SECONDS" \
+  'BEGIN {exit !(value ~ /^[0-9]+([.][0-9]+)?$/ && value > 0)}'; then
+  echo "BACKUP_INTERRUPTION_INTERVAL_SECONDS must be greater than zero." >&2
+  exit 1
+fi
+
+for command in awk dd diff docker grep head jq od sleep tr unlink; do
+  if ! command -v "$command" >/dev/null 2>&1; then
+    echo "Required command is unavailable: $command" >&2
+    exit 1
+  fi
+done
+
+bucket="$BACKUP_BUCKET_PREFIX-$LABEL"
+corrupt_bucket="$bucket-corrupt"
+interrupt_bucket="$bucket-interrupt"
+
+for candidate in "$bucket" "$corrupt_bucket" "$interrupt_bucket"; do
+  if ((${#candidate} > 63)); then
+    echo "Derived S3 bucket name exceeds 63 characters: $candidate" >&2
+    exit 1
+  fi
+done
+
+runtime_dir="$ROOT/tmp/backup-s3/$LOAD_PROJECT/$LABEL"
+output_dir="$ROOT/output/backups-s3/$LABEL"
+mkdir -p "$runtime_dir" "$output_dir"
+chmod 700 "$ROOT/tmp" "$ROOT/tmp/backup-s3" \
+  "$ROOT/tmp/backup-s3/$LOAD_PROJECT" "$runtime_dir" \
+  "$ROOT/output" "$ROOT/output/backups-s3" "$output_dir"
+
+export BACKUP_RUNTIME_DIR="$runtime_dir"
+export BACKUP_HOST_UID
+export BACKUP_HOST_GID
+BACKUP_HOST_UID=$(id -u)
+BACKUP_HOST_GID=$(id -g)
+
+compose=(
+  docker compose
+  --env-file "$ENV_FILE"
+  -p "$LOAD_PROJECT"
+  -f compose.yaml
+  -f compose.load.yaml
+  -f compose.backup.yaml
+  --profile backup
+)
+
+service_ids() {
+  "${compose[@]}" ps --all -q "$1"
+}
+
+assert_scope() {
+  local container_id=$1
+  local expected_service=$2
+  local observed_project observed_service
+
+  observed_project=$(
+    docker inspect --format '{{index .Config.Labels "com.docker.compose.project"}}' \
+      "$container_id"
+  )
+  observed_service=$(
+    docker inspect --format '{{index .Config.Labels "com.docker.compose.service"}}' \
+      "$container_id"
+  )
+
+  if [[ "$observed_project" != "$LOAD_PROJECT" ||
+    "$observed_service" != "$expected_service" ]]; then
+    echo "Container scope mismatch for $container_id." >&2
+    exit 1
+  fi
+}
+
+mc_run() {
+  "${compose[@]}" run --rm --no-deps -T minio-client "$@"
+}
+
+restic_run_repo() {
+  local repository=$1
+  shift
+  "${compose[@]}" run --rm --no-deps -T \
+    --env "RESTIC_REPOSITORY=$repository" \
+    backup-tools restic "$@"
+}
+
+database_snapshot() {
+  # Variables are intentionally expanded inside the isolated PostGIS container.
+  # shellcheck disable=SC2016
+  "${compose[@]}" exec -T db sh -c \
+    'psql --no-psqlrc --tuples-only --no-align --set ON_ERROR_STOP=1 \
+      --username "$POSTGRES_USER" --dbname "$POSTGRES_DB"' >"$1" <<'SQL'
+BEGIN READ ONLY;
+SELECT 'users' AS table_name, count(*) AS row_count FROM users
+UNION ALL SELECT 'users_tokens', count(*) FROM users_tokens
+UNION ALL SELECT 'help_requests', count(*) FROM help_requests
+UNION ALL SELECT 'messages', count(*) FROM messages
+UNION ALL SELECT 'categories', count(*) FROM categories
+UNION ALL SELECT 'help_assignments', count(*) FROM help_assignments
+UNION ALL SELECT 'activities', count(*) FROM activities
+UNION ALL SELECT 'reports', count(*) FROM reports
+UNION ALL SELECT 'social_identities', count(*) FROM social_identities
+UNION ALL SELECT 'tracking_sessions', count(*) FROM tracking_sessions
+UNION ALL SELECT 'tracking_positions', count(*) FROM tracking_positions
+UNION ALL SELECT 'schema_migrations', count(*) FROM schema_migrations
+ORDER BY table_name;
+COMMIT;
+SQL
+}
+
+wait_for_minio() {
+  local minio_id=$1
+  local deadline=$((SECONDS + BACKUP_TIMEOUT_SECONDS))
+
+  while ((SECONDS < deadline)); do
+    local state health
+    state=$(docker inspect --format '{{.State.Status}}' "$minio_id")
+    health=$(docker inspect --format '{{if .State.Health}}{{.State.Health.Status}}{{end}}' \
+      "$minio_id")
+
+    if [[ "$state" == "running" && "$health" == "healthy" ]]; then
+      return 0
+    fi
+
+    sleep 1
+  done
+
+  echo "Timed out waiting for the scoped MinIO container." >&2
+  return 1
+}
+
+remove_bucket() {
+  local candidate=$1
+  mc_run rb --force "local/$candidate" >/dev/null 2>&1 || true
+}
+
+remove_bucket_and_verify() {
+  local candidate=$1
+
+  mc_run rb --force "local/$candidate" >/dev/null
+
+  if mc_run stat "local/$candidate" >/dev/null 2>&1; then
+    echo "Temporary MinIO bucket was not removed: $candidate" >&2
+    exit 1
+  fi
+}
+
+remove_interrupt_container() {
+  if [[ -n "${interrupt_container_id:-}" ]] &&
+    docker inspect "$interrupt_container_id" >/dev/null 2>&1; then
+    assert_scope "$interrupt_container_id" backup-tools
+    docker stop --time 1 "$interrupt_container_id" >/dev/null 2>&1 || true
+    docker rm "$interrupt_container_id" >/dev/null 2>&1 || true
+  fi
+}
+
+drop_drill_database() {
+  if [[ "${drill_database_created:-false}" == "true" ]]; then
+    "${compose[@]}" exec -T db \
+      dropdb --username "$POSTGRES_USER" --if-exists "$drill_db" >/dev/null 2>&1 || true
+  fi
+}
+
+cleanup() {
+  local status=$?
+  trap - EXIT HUP INT TERM
+  drop_drill_database
+  remove_interrupt_container
+
+  if [[ "${corrupt_bucket_created:-false}" == "true" ]]; then
+    remove_bucket "$corrupt_bucket"
+  fi
+
+  if [[ "${interrupt_bucket_created:-false}" == "true" ]]; then
+    remove_bucket "$interrupt_bucket"
+  fi
+
+  exit "$status"
+}
+
+trap cleanup EXIT HUP INT TERM
+
+for service in minio-permissions minio minio-client backup-tools; do
+  while IFS= read -r existing_id; do
+    [[ -n "$existing_id" ]] && assert_scope "$existing_id" "$service"
+  done < <(service_ids "$service")
+done
+
+database_snapshot "$output_dir/database-before.txt"
+
+"${compose[@]}" build backup-tools minio minio-client \
+  >"$output_dir/backup-images-build.txt"
+"${compose[@]}" up -d --wait minio >"$output_dir/minio-up.txt"
+minio_id=$(service_ids minio | head -n 1)
+assert_scope "$minio_id" minio
+wait_for_minio "$minio_id"
+
+if mc_run stat "local/$bucket" >/dev/null 2>&1; then
+  echo "Refusing to overwrite retained canonical bucket: $bucket" >&2
+  exit 1
+fi
+
+mc_run mb "local/$bucket" >"$output_dir/canonical-bucket-create.txt"
+canonical_repository="s3:http://minio:9000/$bucket"
+restic_run_repo "$canonical_repository" init >"$output_dir/restic-init.txt"
+
+restic_run_repo "$canonical_repository" \
+  backup \
+  --json \
+  --host who-need-help-local \
+  --tag "$LABEL" \
+  --stdin-filename database.dump \
+  --stdin-from-command \
+  -- \
+  pg_dump \
+  --host db \
+  --username "$POSTGRES_USER" \
+  --dbname "$POSTGRES_DB" \
+  --format custom \
+  --no-owner \
+  >"$output_dir/backup.jsonl"
+
+restic_run_repo "$canonical_repository" snapshots --json --tag "$LABEL" \
+  >"$output_dir/snapshots.json"
+
+if ! jq -e --arg label "$LABEL" '
+  length == 1 and
+  .[0].tags == [$label] and
+  (.[0].id | length) == 64
+' "$output_dir/snapshots.json" >/dev/null; then
+  echo "The canonical encrypted backup did not create exactly one tagged snapshot." >&2
+  exit 1
+fi
+
+snapshot_id=$(jq -r '.[0].id' "$output_dir/snapshots.json")
+
+restic_run_repo "$canonical_repository" check --read-data \
+  >"$output_dir/canonical-check.txt" 2>&1
+restic_run_repo "$canonical_repository" ls --json "$snapshot_id" \
+  >"$output_dir/snapshot-files.jsonl"
+
+if ! jq -s -e '
+  any(
+    .[];
+    .struct_type == "node" and
+    .path == "/database.dump" and
+    .type == "file" and
+    .size > 0
+  )
+' "$output_dir/snapshot-files.jsonl" >/dev/null; then
+  echo "The encrypted snapshot does not contain a non-empty database.dump." >&2
+  exit 1
+fi
+
+mc_run ls --recursive --json "local/$bucket" \
+  >"$output_dir/minio-objects.jsonl"
+
+if ! jq -s -e '
+  length > 0 and
+  any(.[]; (.key // "") | startswith("data/"))
+' "$output_dir/minio-objects.jsonl" >/dev/null; then
+  echo "MinIO did not retain encrypted Restic data objects." >&2
+  exit 1
+fi
+
+pack_key=$(
+  jq -sr '
+    [.[] | select((.key // "") | startswith("data/")) | .key]
+    | sort
+    | first
+  ' "$output_dir/minio-objects.jsonl"
+)
+
+mc_run cat "local/$bucket/$pack_key" |
+  dd of="$runtime_dir/encrypted-prefix.bin" bs=1 count=16 status=none
+od -An -tx1 -v "$runtime_dir/encrypted-prefix.bin" |
+  tr -d ' \n' >"$output_dir/encrypted-prefix.hex"
+
+if grep -aFq 'PGDMP' "$runtime_dir/encrypted-prefix.bin"; then
+  echo "A Restic data object exposed the PostgreSQL custom-format header." >&2
+  exit 1
+fi
+
+restic_run_repo "$canonical_repository" dump "$snapshot_id" /database.dump |
+  "${compose[@]}" exec -T db pg_restore --list \
+    >"$output_dir/pg-restore-list.txt"
+
+drill_db="wnh_s3_restore_${LABEL//-/_}_$$"
+"${compose[@]}" exec -T db \
+  createdb \
+  --username "$POSTGRES_USER" \
+  --template template0 \
+  "$drill_db"
+drill_database_created=true
+
+restic_run_repo "$canonical_repository" dump "$snapshot_id" /database.dump |
+  "${compose[@]}" exec -T db \
+    pg_restore \
+    --username "$POSTGRES_USER" \
+    --dbname "$drill_db" \
+    --exit-on-error \
+    --no-owner \
+    --no-privileges
+
+"${compose[@]}" exec -T db \
+  psql --no-psqlrc --tuples-only --no-align --set ON_ERROR_STOP=1 \
+  --username "$POSTGRES_USER" --dbname "$drill_db" \
+  >"$output_dir/restored-database.json" <<'SQL'
+SELECT json_build_object(
+  'public_table_count',
+    (
+      SELECT count(*)
+      FROM pg_tables
+      WHERE schemaname = 'public'
+        AND tablename <> 'spatial_ref_sys'
+    ),
+  'migration_count', (SELECT count(*) FROM schema_migrations),
+  'user_count', (SELECT count(*) FROM users),
+  'request_count', (SELECT count(*) FROM help_requests),
+  'message_count', (SELECT count(*) FROM messages),
+  'category_count', (SELECT count(*) FROM categories),
+  'postgis_version', PostGIS_Lib_Version()
+);
+SQL
+
+if ! jq -e '
+  .public_table_count > 0 and
+  .migration_count > 0 and
+  .category_count > 0 and
+  (.postgis_version | type == "string" and length > 0)
+' "$output_dir/restored-database.json" >/dev/null; then
+  echo "The fresh restore database failed structural validation." >&2
+  exit 1
+fi
+
+case "$DATABASE_URL" in
+  *\?*)
+    database_base=${DATABASE_URL%%\?*}
+    database_query="?${DATABASE_URL#*\?}"
+    ;;
+
+  *)
+    database_base=$DATABASE_URL
+    database_query=
+    ;;
+esac
+
+database_prefix=${database_base%/*}
+
+if [[ "$database_prefix" == "$database_base" ]]; then
+  echo "Could not derive the temporary drill DATABASE_URL." >&2
+  exit 1
+fi
+
+drill_database_url="$database_prefix/$drill_db$database_query"
+
+"${compose[@]}" run --rm --no-deps \
+  --env APP_ROLE=migrate \
+  --env "DATABASE_URL=$drill_database_url" \
+  migrate /app/bin/migrate \
+  >"$output_dir/restore-migrate.txt"
+
+"${compose[@]}" run --rm --no-deps \
+  --env APP_ROLE=migrate \
+  --env "DATABASE_URL=$drill_database_url" \
+  migrate /app/bin/who_need_help eval 'WhoNeedHelp.Release.await_migrations()' \
+  >"$output_dir/restore-migration-readiness.txt"
+
+"${compose[@]}" exec -T db \
+  dropdb --username "$POSTGRES_USER" "$drill_db"
+drill_database_created=false
+
+remaining=$(
+  "${compose[@]}" exec -T db \
+    psql --no-psqlrc --tuples-only --no-align --set ON_ERROR_STOP=1 \
+    --username "$POSTGRES_USER" --dbname postgres \
+    --command "SELECT count(*) FROM pg_database WHERE datname = '$drill_db';"
+)
+
+if [[ "$remaining" != "0" ]]; then
+  echo "Restore drill database was not removed: $drill_db" >&2
+  exit 1
+fi
+
+mc_run mb "local/$corrupt_bucket" >"$output_dir/corrupt-bucket-create.txt"
+corrupt_bucket_created=true
+mc_run mirror "local/$bucket" "local/$corrupt_bucket" \
+  >"$output_dir/corrupt-mirror.txt"
+mc_run cp "local/$corrupt_bucket/config" /work/corrupt-config \
+  >"$output_dir/corrupt-download.txt"
+
+first_byte=$(od -An -tu1 -N1 "$runtime_dir/corrupt-config" | tr -d ' ')
+
+if [[ "$first_byte" == "0" ]]; then
+  printf '\001' | dd of="$runtime_dir/corrupt-config" bs=1 count=1 conv=notrunc status=none
+else
+  printf '\000' | dd of="$runtime_dir/corrupt-config" bs=1 count=1 conv=notrunc status=none
+fi
+
+mc_run cp /work/corrupt-config "local/$corrupt_bucket/config" \
+  >"$output_dir/corrupt-upload.txt"
+corrupt_repository="s3:http://minio:9000/$corrupt_bucket"
+
+set +e
+restic_run_repo "$corrupt_repository" check --read-data \
+  >"$output_dir/corrupt-check.txt" 2>&1
+corrupt_check_status=$?
+restic_run_repo "$corrupt_repository" dump "$snapshot_id" /database.dump \
+  >"/dev/null" 2>"$output_dir/corrupt-restore.txt"
+corrupt_restore_status=$?
+set -e
+
+if [[ "$corrupt_check_status" -eq 0 || "$corrupt_restore_status" -eq 0 ]]; then
+  echo "The corrupted encrypted repository did not fail closed." >&2
+  exit 1
+fi
+
+remove_bucket_and_verify "$corrupt_bucket"
+corrupt_bucket_created=false
+unlink "$runtime_dir/corrupt-config"
+
+mc_run mb "local/$interrupt_bucket" >"$output_dir/interrupt-bucket-create.txt"
+interrupt_bucket_created=true
+interrupt_repository="s3:http://minio:9000/$interrupt_bucket"
+restic_run_repo "$interrupt_repository" init >"$output_dir/interrupt-init.txt"
+
+interrupt_container="$LOAD_PROJECT-backup-interrupt-$LABEL"
+
+if docker inspect "$interrupt_container" >/dev/null 2>&1; then
+  echo "Refusing to replace an existing interruption container: $interrupt_container" >&2
+  exit 1
+fi
+
+# The producer variables must expand inside the isolated backup-tools container.
+# shellcheck disable=SC2016
+interrupt_container_id=$(
+  "${compose[@]}" run -d \
+    --name "$interrupt_container" \
+    --no-deps \
+    --env "RESTIC_REPOSITORY=$interrupt_repository" \
+    backup-tools \
+    restic backup \
+    --json \
+    --host who-need-help-local \
+    --tag "$LABEL-interrupted" \
+    --stdin-filename interrupted.bin \
+    --stdin-from-command \
+    -- \
+    /bin/sh -euc \
+    'i=0
+     while [ "$i" -lt "$BACKUP_INTERRUPTION_CHUNKS" ]; do
+       head -c "$BACKUP_INTERRUPTION_CHUNK_BYTES" /dev/urandom
+       sleep "$BACKUP_INTERRUPTION_INTERVAL_SECONDS"
+       i=$((i + 1))
+     done'
+)
+assert_scope "$interrupt_container_id" backup-tools
+
+upload_deadline=$((SECONDS + BACKUP_TIMEOUT_SECONDS))
+uploaded_data_objects=0
+
+while ((SECONDS < upload_deadline)); do
+  mc_run ls --recursive --json "local/$interrupt_bucket/data" \
+    >"$output_dir/interrupt-objects-current.jsonl" 2>/dev/null || true
+  uploaded_data_objects=$(
+    jq -s '[.[] | select(.type == "file")] | length' \
+      "$output_dir/interrupt-objects-current.jsonl"
+  )
+
+  if ((uploaded_data_objects > 0)); then
+    break
+  fi
+
+  if [[ "$(docker inspect --format '{{.State.Running}}' "$interrupt_container_id")" != "true" ]]; then
+    echo "Interruption producer exited before an uploaded data object was observed." >&2
+    exit 1
+  fi
+
+  sleep 1
+done
+
+if ((uploaded_data_objects == 0)); then
+  echo "Timed out waiting for the interruption upload to reach MinIO." >&2
+  exit 1
+fi
+
+docker stop --time 1 "$interrupt_container_id" >"$output_dir/interrupt-stop.txt"
+docker inspect "$interrupt_container_id" |
+  jq '.[0] | {
+    id: .Id,
+    project: .Config.Labels["com.docker.compose.project"],
+    service: .Config.Labels["com.docker.compose.service"],
+    exit_code: .State.ExitCode,
+    state: .State.Status
+  }' >"$output_dir/interrupt-container.json"
+docker logs "$interrupt_container_id" >"$output_dir/interrupt-backup.log" 2>&1
+
+if ! jq -e '.exit_code != 0 and .state == "exited"' \
+  "$output_dir/interrupt-container.json" >/dev/null; then
+  echo "The interrupted upload container did not exit unsuccessfully." >&2
+  exit 1
+fi
+
+restic_run_repo "$interrupt_repository" snapshots \
+  --json --tag "$LABEL-interrupted" \
+  >"$output_dir/interrupt-snapshots.json"
+
+if ! jq -e 'length == 0' "$output_dir/interrupt-snapshots.json" >/dev/null; then
+  echo "An interrupted upload published a restorable snapshot." >&2
+  exit 1
+fi
+
+mc_run ls --incomplete --recursive --json "local/$interrupt_bucket" \
+  >"$output_dir/interrupt-incomplete-uploads.jsonl" 2>/dev/null || true
+restic_run_repo "$interrupt_repository" check --read-data \
+  >"$output_dir/interrupt-check-before-prune.txt" 2>&1
+restic_run_repo "$interrupt_repository" prune \
+  >"$output_dir/interrupt-prune.txt" 2>&1
+restic_run_repo "$interrupt_repository" check --read-data \
+  >"$output_dir/interrupt-check-after-prune.txt" 2>&1
+
+docker rm "$interrupt_container_id" >"$output_dir/interrupt-remove.txt"
+interrupt_container_id=
+remove_bucket_and_verify "$interrupt_bucket"
+interrupt_bucket_created=false
+
+database_snapshot "$output_dir/database-after.txt"
+
+if ! diff -u "$output_dir/database-before.txt" "$output_dir/database-after.txt" \
+  >"$output_dir/database-diff.txt"; then
+  echo "The encrypted backup drill changed source database counts." >&2
+  exit 1
+fi
+
+minio_api=$("${compose[@]}" port minio 9000 | head -n 1)
+minio_console=$("${compose[@]}" port minio 9001 | head -n 1)
+
+if [[ ! "$minio_api" =~ ^127[.]0[.]0[.]1:[1-9][0-9]*$ ||
+  ! "$minio_console" =~ ^127[.]0[.]0[.]1:[1-9][0-9]*$ ]]; then
+  echo "MinIO ports are not bound to observed loopback addresses." >&2
+  exit 1
+fi
+
+jq -n \
+  --arg run_id "$LABEL" \
+  --arg bucket "$bucket" \
+  --arg snapshot_id "$snapshot_id" \
+  --arg minio_api "http://$minio_api" \
+  --arg minio_console "http://$minio_console" \
+  --argjson corrupt_check_exit "$corrupt_check_status" \
+  --argjson corrupt_restore_exit "$corrupt_restore_status" \
+  --argjson interrupted_uploaded_objects "$uploaded_data_objects" \
+  '{
+    run_id: $run_id,
+    retained_bucket: $bucket,
+    snapshot_id: $snapshot_id,
+    encrypted_repository_check: "passed",
+    fresh_database_restore: "passed",
+    source_database_count_diff_bytes: 0,
+    corrupted_check_exit: $corrupt_check_exit,
+    corrupted_restore_exit: $corrupt_restore_exit,
+    interrupted_uploaded_objects: $interrupted_uploaded_objects,
+    interrupted_snapshot_count: 0,
+    interrupted_repository_check_after_prune: "passed",
+    minio_api: $minio_api,
+    minio_console: $minio_console
+  }' >"$output_dir/summary.json"
+
+trap - EXIT HUP INT TERM
+
+printf 'Encrypted S3 backup evidence: %s\n' "$output_dir"
+printf 'Retained MinIO bucket: %s\nSnapshot: %s\n' "$bucket" "$snapshot_id"
+printf 'MinIO API: http://%s\nMinIO console: http://%s\n' \
+  "$minio_api" "$minio_console"
diff --git a/scripts/ensure-local-load-env.sh b/scripts/ensure-local-load-env.sh
index 4f72e94..1f893ab 100755
--- a/scripts/ensure-local-load-env.sh
+++ b/scripts/ensure-local-load-env.sh
@@ -28,6 +28,16 @@ if [ -f "$ENV_FILE" ]; then
   needs_observability_timeout=true
   needs_observability_grafana_user=true
   needs_observability_grafana_password=true
+  needs_backup_minio_api_port=true
+  needs_backup_minio_console_port=true
+  needs_backup_minio_root_user=true
+  needs_backup_minio_root_password=true
+  needs_backup_restic_password=true
+  needs_backup_bucket_prefix=true
+  needs_backup_timeout=true
+  needs_backup_interruption_chunks=true
+  needs_backup_interruption_chunk_bytes=true
+  needs_backup_interruption_interval=true
 
   grep -q '^LOAD_FIXTURE_PASSWORD=' "$ENV_FILE" && needs_fixture_password=false
   grep -q '^LOAD_RESILIENCE_RECOVERY_TIMEOUT_SECONDS=' "$ENV_FILE" &&
@@ -53,6 +63,26 @@ if [ -f "$ENV_FILE" ]; then
     needs_observability_grafana_user=false
   grep -q '^OBSERVABILITY_GRAFANA_ADMIN_PASSWORD=' "$ENV_FILE" &&
     needs_observability_grafana_password=false
+  grep -q '^BACKUP_MINIO_API_PORT=' "$ENV_FILE" &&
+    needs_backup_minio_api_port=false
+  grep -q '^BACKUP_MINIO_CONSOLE_PORT=' "$ENV_FILE" &&
+    needs_backup_minio_console_port=false
+  grep -q '^BACKUP_MINIO_ROOT_USER=' "$ENV_FILE" &&
+    needs_backup_minio_root_user=false
+  grep -q '^BACKUP_MINIO_ROOT_PASSWORD=' "$ENV_FILE" &&
+    needs_backup_minio_root_password=false
+  grep -q '^BACKUP_RESTIC_PASSWORD=' "$ENV_FILE" &&
+    needs_backup_restic_password=false
+  grep -q '^BACKUP_BUCKET_PREFIX=' "$ENV_FILE" &&
+    needs_backup_bucket_prefix=false
+  grep -q '^BACKUP_TIMEOUT_SECONDS=' "$ENV_FILE" &&
+    needs_backup_timeout=false
+  grep -q '^BACKUP_INTERRUPTION_CHUNKS=' "$ENV_FILE" &&
+    needs_backup_interruption_chunks=false
+  grep -q '^BACKUP_INTERRUPTION_CHUNK_BYTES=' "$ENV_FILE" &&
+    needs_backup_interruption_chunk_bytes=false
+  grep -q '^BACKUP_INTERRUPTION_INTERVAL_SECONDS=' "$ENV_FILE" &&
+    needs_backup_interruption_interval=false
 
   if [ "$needs_fixture_password" = false ] &&
     [ "$needs_resilience_timeout" = false ] &&
@@ -66,7 +96,17 @@ if [ -f "$ENV_FILE" ]; then
     [ "$needs_observability_evaluation_interval" = false ] &&
     [ "$needs_observability_timeout" = false ] &&
     [ "$needs_observability_grafana_user" = false ] &&
-    [ "$needs_observability_grafana_password" = false ]; then
+    [ "$needs_observability_grafana_password" = false ] &&
+    [ "$needs_backup_minio_api_port" = false ] &&
+    [ "$needs_backup_minio_console_port" = false ] &&
+    [ "$needs_backup_minio_root_user" = false ] &&
+    [ "$needs_backup_minio_root_password" = false ] &&
+    [ "$needs_backup_restic_password" = false ] &&
+    [ "$needs_backup_bucket_prefix" = false ] &&
+    [ "$needs_backup_timeout" = false ] &&
+    [ "$needs_backup_interruption_chunks" = false ] &&
+    [ "$needs_backup_interruption_chunk_bytes" = false ] &&
+    [ "$needs_backup_interruption_interval" = false ]; then
     echo ".env.load already exists; no secret or experiment input was changed."
     exit 0
   fi
@@ -74,6 +114,9 @@ if [ -f "$ENV_FILE" ]; then
   umask 077
   load_fixture_password=
   observability_grafana_admin_password=
+  backup_minio_root_user=
+  backup_minio_root_password=
+  backup_restic_password=
 
   if [ "$needs_fixture_password" = true ]; then
     load_fixture_password=$(openssl rand -hex 24)
@@ -83,6 +126,18 @@ if [ -f "$ENV_FILE" ]; then
     observability_grafana_admin_password=$(openssl rand -hex 32)
   fi
 
+  if [ "$needs_backup_minio_root_user" = true ]; then
+    backup_minio_root_user="wnh$(openssl rand -hex 12)"
+  fi
+
+  if [ "$needs_backup_minio_root_password" = true ]; then
+    backup_minio_root_password=$(openssl rand -hex 32)
+  fi
+
+  if [ "$needs_backup_restic_password" = true ]; then
+    backup_restic_password=$(openssl rand -hex 32)
+  fi
+
   {
     if [ "$needs_fixture_password" = true ]; then
       printf '\n# Added by the authenticated-load profile upgrade.\n'
@@ -156,17 +211,76 @@ if [ -f "$ENV_FILE" ]; then
       printf 'OBSERVABILITY_GRAFANA_ADMIN_PASSWORD=%s\n' \
         "$observability_grafana_admin_password"
     fi
+
+    if [ "$needs_backup_minio_api_port" = true ] ||
+      [ "$needs_backup_minio_console_port" = true ] ||
+      [ "$needs_backup_minio_root_user" = true ] ||
+      [ "$needs_backup_minio_root_password" = true ] ||
+      [ "$needs_backup_restic_password" = true ] ||
+      [ "$needs_backup_bucket_prefix" = true ] ||
+      [ "$needs_backup_timeout" = true ] ||
+      [ "$needs_backup_interruption_chunks" = true ] ||
+      [ "$needs_backup_interruption_chunk_bytes" = true ] ||
+      [ "$needs_backup_interruption_interval" = true ]; then
+      printf '\n# Added by the encrypted local backup-profile upgrade.\n'
+    fi
+
+    if [ "$needs_backup_minio_api_port" = true ]; then
+      printf 'BACKUP_MINIO_API_PORT=0\n'
+    fi
+
+    if [ "$needs_backup_minio_console_port" = true ]; then
+      printf 'BACKUP_MINIO_CONSOLE_PORT=0\n'
+    fi
+
+    if [ "$needs_backup_minio_root_user" = true ]; then
+      printf 'BACKUP_MINIO_ROOT_USER=%s\n' "$backup_minio_root_user"
+    fi
+
+    if [ "$needs_backup_minio_root_password" = true ]; then
+      printf 'BACKUP_MINIO_ROOT_PASSWORD=%s\n' "$backup_minio_root_password"
+    fi
+
+    if [ "$needs_backup_restic_password" = true ]; then
+      printf 'BACKUP_RESTIC_PASSWORD=%s\n' "$backup_restic_password"
+    fi
+
+    if [ "$needs_backup_bucket_prefix" = true ]; then
+      printf 'BACKUP_BUCKET_PREFIX=wnh-backup\n'
+    fi
+
+    if [ "$needs_backup_timeout" = true ]; then
+      printf 'BACKUP_TIMEOUT_SECONDS=120\n'
+    fi
+
+    if [ "$needs_backup_interruption_chunks" = true ]; then
+      printf 'BACKUP_INTERRUPTION_CHUNKS=300\n'
+    fi
+
+    if [ "$needs_backup_interruption_chunk_bytes" = true ]; then
+      printf 'BACKUP_INTERRUPTION_CHUNK_BYTES=1048576\n'
+    fi
+
+    if [ "$needs_backup_interruption_interval" = true ]; then
+      printf 'BACKUP_INTERRUPTION_INTERVAL_SECONDS=0.1\n'
+    fi
   } >>"$ENV_FILE"
   chmod 600 "$ENV_FILE"
   unset load_fixture_password observability_grafana_admin_password \
+    backup_minio_root_user backup_minio_root_password backup_restic_password \
     needs_fixture_password needs_resilience_timeout \
     needs_resilience_interval needs_resilience_request_timeout \
     needs_traefik_retry_attempts needs_observability_prometheus_port \
     needs_observability_alertmanager_port needs_observability_grafana_port \
     needs_observability_scrape_interval needs_observability_evaluation_interval \
     needs_observability_timeout needs_observability_grafana_user \
-    needs_observability_grafana_password
-  echo "Added missing load/resilience/observability inputs to ignored .env.load."
+    needs_observability_grafana_password needs_backup_minio_api_port \
+    needs_backup_minio_console_port needs_backup_minio_root_user \
+    needs_backup_minio_root_password needs_backup_restic_password \
+    needs_backup_bucket_prefix needs_backup_timeout \
+    needs_backup_interruption_chunks needs_backup_interruption_chunk_bytes \
+    needs_backup_interruption_interval
+  echo "Added missing load/resilience/observability/backup inputs to ignored .env.load."
   exit 0
 fi
 
@@ -183,6 +297,9 @@ release_cookie=$(openssl rand -hex 64)
 metrics_token=$(openssl rand -hex 32)
 load_fixture_password=$(openssl rand -hex 24)
 observability_grafana_admin_password=$(openssl rand -hex 32)
+backup_minio_root_user="wnh$(openssl rand -hex 12)"
+backup_minio_root_password=$(openssl rand -hex 32)
+backup_restic_password=$(openssl rand -hex 32)
 database_url="ecto://wnh_load:${postgres_password}@db/who_need_help_load"
 temporary=$(mktemp "${ENV_FILE}.XXXXXX")
 trap 'rm -f "$temporary"' EXIT HUP INT TERM
@@ -195,6 +312,9 @@ RELEASE_COOKIE_VALUE=$release_cookie \
 METRICS_TOKEN_VALUE=$metrics_token \
 LOAD_FIXTURE_PASSWORD_VALUE=$load_fixture_password \
 OBSERVABILITY_GRAFANA_ADMIN_PASSWORD_VALUE=$observability_grafana_admin_password \
+BACKUP_MINIO_ROOT_USER_VALUE=$backup_minio_root_user \
+BACKUP_MINIO_ROOT_PASSWORD_VALUE=$backup_minio_root_password \
+BACKUP_RESTIC_PASSWORD_VALUE=$backup_restic_password \
   perl -0pe '
     s/GENERATE_POSTGRES_PASSWORD/$ENV{POSTGRES_PASSWORD_VALUE}/g;
     s/GENERATE_DATABASE_URL/$ENV{DATABASE_URL_VALUE}/g;
@@ -204,6 +324,9 @@ OBSERVABILITY_GRAFANA_ADMIN_PASSWORD_VALUE=$observability_grafana_admin_password
     s/GENERATE_METRICS_TOKEN/$ENV{METRICS_TOKEN_VALUE}/g;
     s/GENERATE_LOAD_FIXTURE_PASSWORD/$ENV{LOAD_FIXTURE_PASSWORD_VALUE}/g;
     s/GENERATE_OBSERVABILITY_GRAFANA_ADMIN_PASSWORD/$ENV{OBSERVABILITY_GRAFANA_ADMIN_PASSWORD_VALUE}/g;
+    s/GENERATE_BACKUP_MINIO_ROOT_USER/$ENV{BACKUP_MINIO_ROOT_USER_VALUE}/g;
+    s/GENERATE_BACKUP_MINIO_ROOT_PASSWORD/$ENV{BACKUP_MINIO_ROOT_PASSWORD_VALUE}/g;
+    s/GENERATE_BACKUP_RESTIC_PASSWORD/$ENV{BACKUP_RESTIC_PASSWORD_VALUE}/g;
   ' "$TEMPLATE" >"$temporary"
 
 if grep -Eq '^[A-Z0-9_]+=GENERATE_' "$temporary"; then
@@ -215,6 +338,8 @@ chmod 600 "$temporary"
 mv "$temporary" "$ENV_FILE"
 trap - EXIT HUP INT TERM
 unset postgres_password secret_key_base handover_secret release_cookie metrics_token \
-  load_fixture_password observability_grafana_admin_password database_url
+  load_fixture_password observability_grafana_admin_password \
+  backup_minio_root_user backup_minio_root_password backup_restic_password \
+  database_url
 
 echo "Generated independent load-profile secrets in ignored .env.load."
diff --git a/scripts/quality.sh b/scripts/quality.sh
index 5c4ce46..ca7b500 100755
--- a/scripts/quality.sh
+++ b/scripts/quality.sh
@@ -18,6 +18,9 @@ quality_image="who-need-help:quality-$run_id"
 assets_image="who-need-help:assets-audit-$run_id"
 e2e_image="who-need-help:e2e-audit-$run_id"
 release_image="who-need-help:security-$run_id"
+backup_image="who-need-help:backup-audit-$run_id"
+minio_image="who-need-help:minio-audit-$run_id"
+mc_image="who-need-help:mc-audit-$run_id"
 scan_dir=$(mktemp -d "${TMPDIR:-/tmp}/wnh-quality-scan.XXXXXX")
 scan_list="${scan_dir}.files"
 scan_tar="${scan_dir}.tar"
@@ -32,6 +35,7 @@ compose="docker compose -p $project -f $ROOT/compose.quality.yaml"
 cleanup() {
   $compose down --volumes --remove-orphans >/dev/null 2>&1 || true
   docker image rm "$quality_image" "$assets_image" "$e2e_image" "$release_image" \
+    "$backup_image" "$minio_image" "$mc_image" \
     >/dev/null 2>&1 || true
   rm -rf "$scan_dir" "$scan_list" "$scan_tar"
 }
@@ -49,7 +53,8 @@ docker run --rm \
   $(find scripts -type f -name '*.sh' -print | sort)
 
 echo "Checking Dockerfiles with Hadolint 2.14.0"
-for dockerfile in Dockerfile android/Dockerfile e2e/Dockerfile; do
+for dockerfile in Dockerfile Dockerfile.backup Dockerfile.minio \
+  android/Dockerfile e2e/Dockerfile; do
   docker run --rm --interactive "$HADOLINT_IMAGE" \
     hadolint --failure-threshold warning - <"$dockerfile"
 done
@@ -73,6 +78,13 @@ OBSERVABILITY_RUNTIME_DIR="$scan_dir/observability-runtime" \
   docker compose --env-file .env.load.example \
   -f compose.yaml -f compose.load.yaml -f compose.observability.yaml \
   --profile observability config --quiet
+mkdir -p "$scan_dir/backup-runtime"
+BACKUP_RUNTIME_DIR="$scan_dir/backup-runtime" \
+BACKUP_HOST_UID="$(id -u)" \
+BACKUP_HOST_GID="$(id -g)" \
+  docker compose --env-file .env.load.example \
+  -f compose.yaml -f compose.load.yaml -f compose.backup.yaml \
+  --profile backup config --quiet
 docker compose -p "$project" -f compose.quality.yaml config --quiet
 
 echo "Validating local observability configuration"
@@ -161,6 +173,76 @@ docker run --rm "$assets_image" npm audit --audit-level=high
 docker build --tag "$e2e_image" e2e
 docker run --rm "$e2e_image" npm audit --audit-level=high
 
+echo "Building and scanning the pinned non-root backup tool image"
+docker build --tag "$backup_image" --file Dockerfile.backup .
+test "$(docker image inspect --format '{{.Config.User}}' "$backup_image")" = \
+  "10001:10001"
+backup_versions=$(docker run --rm \
+  --user 10001:10001 \
+  --read-only \
+  --tmpfs /tmp \
+  "$backup_image" \
+  sh -euc 'restic version; pg_dump --version; test "$(id -u)" = 10001')
+printf '%s\n' "$backup_versions"
+printf '%s\n' "$backup_versions" |
+  grep -F 'restic 0.19.1 compiled with go1.26.5' >/dev/null
+printf '%s\n' "$backup_versions" |
+  grep -F 'pg_dump (PostgreSQL) 18.4' >/dev/null
+docker run --rm \
+  --volume /var/run/docker.sock:/var/run/docker.sock \
+  --volume "$ROOT/.tools/trivy-cache:/root/.cache/trivy" \
+  "$TRIVY_IMAGE" image \
+  --scanners vuln \
+  --severity HIGH,CRITICAL \
+  --ignore-unfixed \
+  --exit-code 1 \
+  "$backup_image"
+
+echo "Building and scanning the pinned non-root MinIO server and client images"
+docker build --target server --tag "$minio_image" --file Dockerfile.minio .
+docker build --target client --tag "$mc_image" --file Dockerfile.minio .
+test "$(docker image inspect --format '{{.Config.User}}' "$minio_image")" = \
+  "10001:10001"
+test "$(docker image inspect --format '{{.Config.User}}' "$mc_image")" = \
+  "10001:10001"
+minio_version=$(docker run --rm \
+  --user 10001:10001 \
+  --read-only \
+  --tmpfs /tmp \
+  "$minio_image" \
+  --version)
+mc_version=$(docker run --rm \
+  --user 10001:10001 \
+  --read-only \
+  --tmpfs /tmp \
+  "$mc_image" \
+  --version)
+printf '%s\n' "$minio_version"
+printf '%s\n' "$mc_version"
+printf '%s\n' "$minio_version" |
+  grep -F 'RELEASE.2025-10-15T17-29-55Z' >/dev/null
+printf '%s\n' "$minio_version" |
+  grep -F 'commit-id=9e49d5e7a648f00e26f2246f4dc28e6b07f8c84a' >/dev/null
+printf '%s\n' "$minio_version" |
+  grep -F 'Runtime: go1.26.5 linux/' >/dev/null
+printf '%s\n' "$mc_version" |
+  grep -F 'RELEASE.2025-08-13T08-35-41Z' >/dev/null
+printf '%s\n' "$mc_version" |
+  grep -F 'commit-id=7394ce0dd2a80935aded936b09fa12cbb3cb8096' >/dev/null
+printf '%s\n' "$mc_version" |
+  grep -F 'Runtime: go1.26.5 linux/' >/dev/null
+for image in "$minio_image" "$mc_image"; do
+  docker run --rm \
+    --volume /var/run/docker.sock:/var/run/docker.sock \
+    --volume "$ROOT/.tools/trivy-cache:/root/.cache/trivy" \
+    "$TRIVY_IMAGE" image \
+    --scanners vuln \
+    --severity HIGH,CRITICAL \
+    --ignore-unfixed \
+    --exit-code 1 \
+    "$image"
+done
+
 echo "Building and scanning the production release image"
 docker build --target release --tag "$release_image" .
 docker run --rm \