Timelocked
local, offline timed-release file encryption
Last verified:
What is Timelocked?
Timelocked is a downloadable offline desktop application for creating and unlocking .timelocked timed-release files. It encrypts files with a key that is locked in an RSW-style time-lock puzzle, requiring sequential computational work to decrypt. The app works entirely locally on your machine with no internet connection needed and no telemetry sent.
Key features include cross-platform support for Windows, macOS (M1-M5 and Intel), and Linux, with portable builds around 3 MB and minimal dependencies. The software is open source with verifiable CLI and TUI workflows, includes integrity checks and Reed-Solomon recovery for corrupted files, and uses XChaCha20-Poly1305 AEAD encryption for both confidentiality and tamper detection.
Timelocked is designed for users who need files to exist now but open later: cryptocurrency users seeking wrench attack defense by time-locking BIP-39 passphrases, individuals planning inheritance handoffs with tamper-evident bags and Safes, journalists protecting sources, legal professionals managing handoffs, or anyone creating delayed gifts, puzzles, enigmas, or fallback releases for investigations or scientific work.
Upcoming features include pause/resume for long unlocks and an Eco mode to cap CPU usage for battery preservation. The app does not require an account, works completely offline, and is free open-source software with a paid Plus version planned for the future.
Timelocked pricing
Pricing model: Freemium
The standard version of Timelocked is free open-source software available for Windows, macOS (M1-M5 and Intel), and Linux from GitHub releases. Timelocked Plus is a planned paid version not yet available. The pricing page lists planned features, a launch discount, and availability updates. Joining the Plus waitlist provides email updates about Plus launch and the launch discount but does not guarantee availability on a specific date.
Timelocked pros
- Fully open source with public code for inspection
- Works completely offline with no internet required
- No account registration needed
- No telemetry or tracking in the app
- Cross-platform: Windows, macOS M1-M5, macOS Intel, Linux
- Very small footprint around 3 MB
- Minimal dependencies for security
- Portable builds require no installation
- XChaCha20-Poly1305 AEAD encryption for confidentiality and integrity
- Reed-Solomon error correction for partial file recovery
- Two authoritative superblock copies for metadata resilience
- CLI and TUI workflows for verification
- Integrity checks fail explicitly on corruption
- Based on Rivest-Shamir-Wagner 1996 time-lock puzzle research
- Free open-source version currently available
- Prevents parallelization attacks - only one CPU core useful
- Tamper-evident seal detects any file modification
- Compatible with older locked files for durability
Timelocked cons
- Unlock time varies by hardware and cannot guarantee exact date/time
- Faster hardware or future quantum computers may reduce delay
- No pause/resume yet - planned for future release
- No Eco mode yet - planned for future release
- Operating system may warn about unsigned app
- Not a backup service - lose both files and content is gone
- Creator can still keep original and access immediately
- Does not prove authorship or provide digital signatures
- Recovery not guaranteed for heavily corrupted files
- Plus paid version not available yet
- Does not stop copying, deleting, or withholding files
- No guarantee of safety in coercion or theft scenarios
Frequently asked questions about Timelocked
Do I need to register an account to use Timelocked?
No. Timelocked is not a cloud service; it is a local application that does not require an account, does not connect to the internet, and includes no telemetry.
Does Timelocked unlock files at an exact date or time?
No. Timelocked enforces 'do this much work' rather than 'unlock at this exact date and time'. The actual duration depends on the machine unlocking it and conditions like power mode, thermal throttling, and background load.
How does Timelocked work technically?
Timelocked turns a file into a .timelocked package by generating a random symmetric key K, encrypting the file with XChaCha20-Poly1305 AEAD, then time-locking K using an RSW-style repeated-squaring puzzle with T iterations. Unlocking performs the sequential work to recover K, then decrypts the payload. Reed-Solomon error correction protects against some corruption.
Can supercomputers or quantum computers break Timelocked?
Faster computers with higher CPU frequencies can complete the work faster, shortening the delay. Quantum computers may recover secret factors used by the time-lock puzzle and unlock files much faster if large practical quantum computers become available. Choose conservative delays with safety margins for important use cases.
Can a timelocked file be hacked before the delay completes?
The goal is for the only realistic way to open a .timelocked file early to be doing the same long sequential computation required for normal unlocking. Timelocked is designed so there is no known practical shortcut to recover the cryptographic key faster than the required sequential work, based on the 1996 Rivest-Shamir-Wagner time-lock puzzles paper.
Can the creator cheat and unlock instantly?
The creator already has the original content at creation time. If they keep a copy or share the key some other way, they can read it immediately. Timelocked is meant to delay access for someone who only has the .timelocked file, including the creator if they delete the original and do not keep the key.
What happens if I lose the original file and the .timelocked file?
Timelocked is not a backup service. If you lose both the original file/message and the .timelocked file, the content is gone permanently. If you lose the original but keep the .timelocked file, you can unlock later and recover it. Keep multiple backups of .timelocked files and app binaries if it matters.
Can corrupted timelocked files be recovered?
Sometimes yes. Timelocked v1 stores Reed-Solomon redundancy so limited damage in the payload region can be repaired. Recovery is not guaranteed for arbitrary corruption and only works when damage stays within the redundancy budget. Two superblock copies help survive some metadata damage. Minor corruption may be recoverable, but Timelocked is not a substitute for backups.
Why does Timelocked use AEAD encryption?
AEAD provides both confidentiality (protecting content until unlock work is done) and integrity/authenticity (detecting tampering and corruption). Without AEAD, modified ciphertext could produce silent bit flips. The time-lock controls when K is obtained; AEAD ensures decrypted output is the exact original bytes once K is obtained.
Does AEAD prove who created a Timelocked file?
No. AEAD can tell you that the file was decrypted with the right key and was not modified, but it cannot tell you who created it. Proving authorship requires a separate digital signature.