Harvest Now, Decrypt Later

The threat in one sentence

Nation-state adversaries are intercepting and storing encrypted enterprise traffic today, at scale, with the intention of decrypting it once quantum computers become capable enough to break the underlying cryptography.

How the attack works

HNDL (Harvest Now, Decrypt Later) is a straightforward two-phase strategy:
Phase 1 — Collection (happening now). An adversary intercepts encrypted network traffic — TLS sessions, VPN tunnels, authentication tokens, credential syncs — and stores the raw ciphertext. Because the traffic is encrypted, it appears worthless. The adversary doesn't need to decrypt it today. Storage is cheap. They simply archive it.
Phase 2 — Decryption (when quantum computers arrive). Once a cryptographically relevant quantum computer exists, the adversary runs Shor's algorithm against the stored ciphertext. The asymmetric key exchange that protected each TLS session — RSA or ECDSA — is broken in hours. The session keys are recovered. The plaintext traffic is decrypted, years after it was originally intercepted.
The result: credentials, certificates, authentication tokens, and sensitive communications that appeared secure at the time of interception become readable retroactively.

Who is doing this

Multiple intelligence agencies and security researchers have publicly documented HNDL-style collection programs. The US National Security Agency's PRISM program (disclosed in 2013) collected internet traffic at scale. China's MSS has been documented intercepting enterprise VPN traffic. The assumption among cryptographers and national security officials is that any nation-state with the resources to run large-scale signals intelligence is storing encrypted traffic against future quantum decryption capability.
This is not a hypothetical future threat. Collection is a present-day activity.

What is at risk

Not all data has equal HNDL exposure. The risk is highest for information that will still be sensitive when quantum computers arrive — roughly a 5-15 year window based on current NIST estimates.
High risk:
  • Long-lived credentials (passwords that rarely change, API keys, service account credentials)
  • Private keys for TLS certificates and code signing
  • Authentication tokens with long validity periods
  • Sensitive communications about unreleased products, M&A activity, or strategic plans
Lower risk:
  • Short-lived session tokens (valid for minutes or hours)
  • One-time codes
  • Data that will be publicly disclosed before quantum computers arrive
Enterprise identity credentials — the usernames and passwords managed by a password manager — sit squarely in the high-risk category. They are long-lived, high-value, and routinely transmitted over encrypted channels that are subject to interception.

How QuantPass defends against HNDL

QuantPass addresses HNDL at two layers:
At rest — Vault credentials are encrypted with ML-KEM-1024 key encapsulation. Even if an adversary captures the encrypted vault blob today, they cannot decrypt it with a future quantum computer because ML-KEM-1024 is not broken by Shor's algorithm.
In transit — Every QuantPass authentication event uses ML-DSA-44 digital signatures. The authentication channel does not rely on RSA or ECDSA key exchange, eliminating the asymmetric key material that HNDL attacks target.
Active defense — ID-01 Auto-Rekey — If a connected enterprise SIEM detects anomalous traffic patterns consistent with credential harvesting, QuantPass automatically re-encrypts the affected vault with a freshly generated ML-KEM-1024 keypair. The old ciphertext — even if already captured — becomes permanently unrecoverable. This is the only commercially available password manager capability that actively responds to HNDL-style collection in real time.

The compliance angle

Several regulatory frameworks are beginning to address HNDL risk explicitly:
  • US Executive Order 14028 (2021) required federal agencies to inventory cryptographic dependencies.
  • NSM-10 (2022) set a 2035 deadline for federal PQC migration and explicitly cited HNDL as a current threat.
  • CISA's Post-Quantum Cryptography Initiative provides guidance for critical infrastructure operators.
Enterprise security teams evaluating QuantPass should expect their auditors and regulators to ask about PQC migration readiness within the next 2-3 years. Adopting QuantPass now creates an audit artifact demonstrating proactive action.