Context

This issue coordinates the Specter DIY Security Hardening Release v1.10.5.

The previous published GitHub release is v1.10.3. A v1.10.4 tag already exists
as a test/update version, so that number is skipped for the public release.

Status: release built, signed and hardware-tested by a second maintainer.
Publication pending (tag + sha256.signed.txt + release page). See
Release build results below.

Release scope decisions

• No release-signing key rotation. Production signer/key set and threshold
  unchanged (verified — see below).
• No signing-key / bootloader-key changes. Bootloader submodule is identical
  to v1.10.3 (b97192322c32f3fc54a93c2049b800e9c21f27c0).
• Ship the review-ready security-hardening / transaction-verification / entropy
  fixes; defer everything still in review to the next release. Fast release was
  prioritised over pulling in more surface.
• Full-card SD-card secure erase/format feature and related SD-card management
  UI are not in this release.

PR merge / review tracker

Merged into the v1.10.5 release (commit b2d87e5)

• docs: add SECURITY.md disclosure policy, refresh security model docs #373 – docs: add SECURITY.md disclosure policy, refresh security model docs — docs: add SECURITY.md disclosure policy, refresh security model docs #373 — 4139dbd
• Documentation: Add link to udev/README.md to mkdocs #345 – docs: link udev/README.md in mkdocs — Documentation: Add link to udev/README.md to mkdocs #345 — 3f3c831
• Reject dead-TRNG output in get_random_bytes (#370) #372 – Reject dead-TRNG output in get_random_bytes (fixes rng: TRNG timeout returns zeros silently; no sanity check in src/rng.py #370) — Reject dead-TRNG output in get_random_bytes (#370) #372 — 65fcb98 — Reviews: ✅ 4 independent
• Update embit to v0.8.2 #376 – Update embit to v0.8.2 — Update embit to v0.8.2 #376 — 2ff670c — Reviews: ✅ 3 independent
• Re-add mixed-inputs warning for multi-wallet transactions #382 – Re-add mixed-inputs warning for multi-wallet transactions — Re-add mixed-inputs warning for multi-wallet transactions #382 — 7223458 — Reviews: ✅ 1 independent · ☑️ 1 Schnuartz self-review
• Fix change-output classification to require verified descriptor derivation #387 – Verify change-output classification cryptographically — Fix change-output classification to require verified descriptor derivation #387 — fc0e32d — Reviews: ✅ 3 independent · final re-review by @maggo83 on 2026-09-02
• Fix reproducible build (#371) #412 – Fix reproducible build (fixes Unable to reproduce build v1.10.3 #371) — Fix reproducible build (#371) #412 — e4266c1

Not in v1.10.5 — deferred to the next release (still open)

• Fix device wipe on final PIN attempt #380 – Fix device wipe on final PIN attempt — Fix device wipe on final PIN attempt #380 — Reviews: ✅ 2 independent · ☑️ 1 Schnuartz self-review
• Fix incomplete secure wipe of QSPI flash #396 – Fix incomplete secure wipe of QSPI flash — Fix incomplete secure wipe of QSPI flash #396 — Reviews: ✅ 2 independent · ☑️ 1 Schnuartz self-review — supersedes accidentally closed Fix incomplete secure wipe of QSPI flash #386
• Use constant-time comparison for security-sensitive MAC/PIN checks #388 – Constant-time MAC/PIN comparisons — Use constant-time comparison for security-sensitive MAC/PIN checks #388 — Reviews: ✅ 2 independent · ☑️ 1 Schnuartz self-review
• feat: warn on disproportionately high transaction fees #392 – Warn on disproportionately high transaction fees — feat: warn on disproportionately high transaction fees #392 — Reviews: ✅ 1 independent · ☑️ 1 Schnuartz self-review — resolve the open Liquid-scope/design comment before merge
• fix: preserve SIGHASH.DEFAULT (0) for taproot signatures #399 – Preserve SIGHASH.DEFAULT (0) for Taproot signatures — fix: preserve SIGHASH.DEFAULT (0) for taproot signatures #399 — Reviews: ✅ 0 independent · ☑️ 1 Schnuartz self-review
• fix: derive Taproot single-sig wallets from BIP86 (m/86'), keep m/84' recovery #405 – Derive Taproot single-sig wallets from BIP86 and preserve legacy recovery — fix: derive Taproot single-sig wallets from BIP86 (m/86'), keep m/84' recovery #405 — Reviews: ✅ 0 independent
• refactor: remove dead experimental.taproot config #403 – refactor: remove dead experimental.taproot config — refactor: remove dead experimental.taproot config #403
• feat: secure file deletion + SD card format + delete_mnemonic error propagation fix #379 – Secure file deletion + mnemonic-deletion error propagation — feat: secure file deletion + SD card format + delete_mnemonic error propagation fix #379 — release gate: split/reduce before merge; full-card SD erase/format out of scope
• Require on-device confirmation for host XPUB requests #381 – Require on-device confirmation for host XPUB requests — Require on-device confirmation for host XPUB requests #381 — waits for a Specter Desktop release + HWW testing

Explicitly out of scope (SD-card management / full-format — later release)

• SD card: BitBox02 backup import/export + secure delete + delete_mnemonic error propagation fix #378 – BitBox02 SD backup/import/export + SD management
• Add safe deletion for SD card transaction and descriptor files #391 – SD-card transaction/descriptor deletion UI
• Delete files and format the card from the SD file picker #404 – Delete files and format the card from the SD file picker
• full-card SD erase/format portion currently bundled into feat: secure file deletion + SD card format + delete_mnemonic error propagation fix #379

Companion-version note for the release changelog: none of the deferred PRs are
required for v1.10.5 to function; no minimum companion versions apply.

Review and merge gates

• Every merged security PR has at least one independent human review after its final security-relevant changes (Reject dead-TRNG output in get_random_bytes (#370) #372: 4, Update embit to v0.8.2 #376: 3, Fix change-output classification to require verified descriptor derivation #387: 3, Re-add mixed-inputs warning for multi-wallet transactions #382: 1 + self-review)
• No unresolved CHANGES_REQUESTED review on a merged release PR
• Correctness/security review threads on merged PRs resolved or dispositioned
• CI green on every merged PR against master
• Selected PRs merged into master
• Full native test suite on final master — python3 test/run_native_tests.py → 80 passed
• Build/test the Unix simulator on final master
• Build STM32 firmware with the final pinned submodules (bootloader b97192322c, f469-disco 9dd8515aaa)
• python3 -m compileall src test → OK (pre-existing flash.py:287 SyntaxWarning only)

Version freeze and release build

• Release commit frozen: b2d87e55338289a258ee985b26c7b064d5b49132
• Firmware version bumped to v1.10.5 (<version:tag10>0101000599</version:tag10>)
• Create the v1.10.5 tag from b2d87e5
• Confirmed no signing-key changes vs the current production key set
• Built from the frozen commit via the reproducible-build flow (pinned diy Docker image, linux/amd64, SPECTER_REPRODUCIBLE_BUILD=1, production pubkeys, bootloader READ_PROTECTION=1 WRITE_PROTECTION=1)
• Two maintainers independently reproduce the build and compare message/hash — reference build reproduced bit-identical; Marco Kruse reproduced the build independently and the signature/message/hash match
• Vendor signatures added with the existing production keys and threshold (k9ert + Mike)
• Bootloader introspection run on the final specter_upgrade.bin (upgrade-generator.py dump); bootloader on-device also checked with STM32CubeProgrammer (Marco Kruse) — matches previous firmwares
• Signature threshold and signer identities verified — 2 / 2, k9ert c8638d869d056ce1b18677e2b0bfaa60 + Mike cf0239e7708148c0fe2bc1ff485d950e, both cryptographically valid over the signing message
• Embedded production keys verified: k9ert, Mike, Stepan, Backup m/99h; main_fw_sig_threshold = 2, bootloader_sig_threshold = 2
• Versions verified: firmware 1.10.5; bootloader unchanged since v1.10.3. Upgrade is firmware-only (no boot section — message has no b… prefix, unlike v1.10.3)
• SHA-256 generated for all binary artifacts (see below)

Final release verification

• Test the final signed binary, not only pre-sign builds — Marco Kruse built with the signatures, updated an existing device and re-ran Fix change-output classification to require verified descriptor derivation #387 and Re-add mixed-inputs warning for multi-wallet transactions #382; warnings as expected
• Repeat the upgrade test from v1.10.3 with the final signed binary — flashed v1.10.3 (with bootloader), applied specter_upgrade_v1.10.5.bin via SD card → upgrade succeeded, Fix change-output classification to require verified descriptor derivation #387 / Re-add mixed-inputs warning for multi-wallet transactions #382 / Add M3Y scanner #335 test vectors unchanged
• Repeat a fresh-board initial flash with the final binary — installed initial_firmware_v1.10.5.bin (signed) on a clean board, bootloader present and correct; re-ran Fix change-output classification to require verified descriptor derivation #387 and Update embit to v0.8.2 #376 (incl. internal, non-public test QRs) → as expected
• Confirmed no unexpected files/commits after the freeze (git log v1.10.3..b2d87e5 = 8 commits, all mapped to the PRs above)
• Release changelog prepared with a security-impact line per security PR
• Review the changelog
• Produce/sign sha256.signed.txt with the current Specter release-signing GPG key
• Create the GitHub release page
• Upload the final binaries, hashes/signatures and verification info
• Publish v1.10.5

Release build results

SHA-256 of the release assets:

fcd23591cd990cc7973861916e5d398ddd8f3f4dea226035d236ffe0e30bb0ea  specter_upgrade_v1.10.5.bin
d207f6d3750e3aacbc98080581934b8d0ebe52eb833f341e0e249d96c0c711d6  specter_upgrade_unsigned_v1.10.5.bin
b46b6b3ea256bc9f9d4da4250c0d6ffdfc1800cbb44a8845810e045c5e8cae01  initial_firmware_v1.10.5.bin

Component hashes (cross-check): bin/specter-diy.hex
b40f676ffce5dde9d1d108164b2c6f669a233eb89a775375d7d89aea71a503b9 ·
bootloader.hex 0869e02baa58c6f8c63ad0e570fbf1283d8aaacec3956bf0fc94fea65ab9caeb ·
startup.hex 14dc7181e98999230c63b40b7613d08d671e783da98381870246141d25db8f49

Remaining before publish

1. Final changelog review.
2. gpg --digest-algo SHA512 --clearsign -o sha256.signed.txt sha256.txt with the release-signing GPG key.
3. git tag v1.10.5 b2d87e55338289a258ee985b26c7b064d5b49132 && git push origin v1.10.5.
4. Create the GitHub release on the tag, upload specter_upgrade_v1.10.5.bin, specter_upgrade_unsigned_v1.10.5.bin, initial_firmware_v1.10.5.bin, sha256.signed.txt, paste the changelog, publish.

Done: reference + independent (Marco Kruse) reproduction match; final signed
binary tested on device — SD-card upgrade from v1.10.3 and clean-board initial
flash, with #387 / #382 / #376 / #335 test vectors re-verified; bootloader
inspected with STM32CubeProgrammer.

Release-workflow note (PR #414)

PR #414's assemble step currently builds specter_upgrade.bin with the
bootloader section (b1.0.2), which produces a different signing message. The
v1.10.5 signatures target the main-firmware-only upgrade, which is what the
published specter_upgrade.bin contains. #414 must be reconciled with the
firmware-only upgrade flow before it is used to drive a release; the initial
firmware still bundles the production bootloader as before.

Notes

This release is deliberately security hardening, not feature expansion. The
wipe/PIN/constant-time PRs (#380, #388, #396) and the fee-warning / Taproot PRs
(#392, #399, #405) were not review-complete at freeze time and move to the next
release.