Long-Term Validation
Long-Term Validation (LTV) is a property of signed PDF documents whereby all information necessary to verify the signature — including certificate chains, revocation data, and timestamps — is embedded within the document itself, enabling verification even after the signing certificate expires.
What it means
Without LTV, verifying an old signature requires contacting the CA's revocation service, which may be offline years later. With LTV, all revocation responses (OCSP staples or CRLs), the full certificate chain, and a qualified timestamp are embedded at signing time. Archival timestamps (PAdES-LTA) further extend validity by timestamping the LTV data itself periodically.
Why it matters for e-signatures
For contracts with multi-year retention requirements — leases, employment agreements, regulatory filings — LTV-enabled documents from SignOwl ensure signatures remain verifiable long after the signing infrastructure changes or certificates expire.
Related terms
Frequently asked questions
How often should archival timestamps be renewed for LTV?
Archival timestamps should be renewed before the hash algorithm used in the previous timestamp is considered weak, typically every 5–10 years based on cryptographic best practices.
Does SignOwl automatically enable LTV for signed documents?
Yes. SignOwl embeds OCSP responses and the complete certificate chain at signing time, satisfying PAdES-LT requirements for long-term verifiability.
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