Tamper-Evident Document Sealing: Cryptographic PDF Protection
Direct Answer
Tamper-evident document sealing in SignCEO protects completed contracts using cryptographic SHA-256 hash algorithms. Once all signers complete their signatures, the final PDF is digitally sealed. If any party attempts to modify text, numbers, or pages after execution, the cryptographic seal breaks immediately.
Guaranteeing Post-Execution Document Integrity
A critical concern in contract enforcement is proving that the document presented in court is the exact, uncorrupted file that all parties agreed to. With traditional paper or basic scanned PDFs, unauthorized modifications or swapped pages can be difficult to disprove.
SignCEO resolves this through cryptographic tamper-evident document sealing. Upon final signature completion, the document content is processed through a cryptographic SHA-256 digest algorithm, generating a unique mathematical fingerprint of the file.
This cryptographic hash is embedded in the permanent certificate of completion. If even a single comma or digit is altered post-execution, recalculating the hash reveals an immediate mismatch, proving document tampering.
- Cryptographic SHA-256 hashing locks document content against post-signing alterations
- Attached certificate of completion records document checksum, timestamps, and IP addresses
- Standard PDF viewers (like Adobe Acrobat) immediately flag unauthorized changes
- Provides indisputable evidentiary defense for legal enforceability under ESIGN and UETA
Forensic Audit Trails Attached to Every File
Every executed document downloaded from SignCEO includes a tamper-evident audit trail certificate detailing signer email addresses, UTC completion timestamps, and unique file identifiers.
Frequently Asked Questions
What does tamper-evident document sealing mean?
It means the document is cryptographically sealed so that any subsequent modification or alteration after signing is immediately detectable.
How can I verify that a signed PDF has not been altered?
You can verify the document’s SHA-256 cryptographic hash against the value recorded on the attached audit certificate of completion.
Does tamper-evident sealing cost extra in SignCEO?
No. Cryptographic SHA-256 sealing and audit trail generation are standard features included on both Standard ($0/mo) and envelope packs (5 for $10 or 25 for $25) plans.
Is tamper evidence required for legal electronic signatures?
Yes. Both the ESIGN Act and state UETA laws require that electronic records remain capable of retention and accurate reproduction without post-signing corruption.
SignCEO Transparent Pricing
Straightforward pricing with zero surprise charges, no arbitrary price hikes, and no required credit card to start:
SignCEO Standard Plan ($0/month)
3 free envelopes every month. Additional envelope packs: 5 for $10 or 25 for $25. Purchased envelopes never expire. Recipients sign free without accounts.
ClientCEO Integration (10 Free/month)
10 free envelopes monthly per unique user for ClientCEO users. 5 envelopes for $10 or 25 for $25. Purchased credits never expire.