Technical dictionary
Harvest Now, Decrypt Later (HNDL)
Adversaries store ciphertext today to decrypt when a quantum computer becomes available.
Definition
HNDL (also “store now, decrypt later”) means long-lived confidentiality is already at risk: recorded TLS, VPN, or archived files may be readable later even if systems look fine today.
Data shelf life—not only Q-Day estimates—should drive migration priority.