Attest vs Zoho Sign

Attest and Zoho Sign at a glance

Zoho Sign is the e-signature product of Zoho Corporation, headquartered in Chennai, India, and it connects with Zoho's other business apps. Attest is built around a different promise: proof anyone can check, on documents only the parties can read. Zoho Sign's prices are as published on its pricing page on October 12, 2026; its other details are as published on its own pages on October 11, 2026.

	Attest	Zoho Sign (as published October 11, 2026)
Who can read your documents	Only you and the people you send them to. Every document is end-to-end encrypted in your browser	Zoho describes AES 256-bit encryption at rest and TLS in transit, and says "Zoho employees cannot view users' data in plain text"
How a signer signs	Approves with a passkey only they control (Face ID, Touch ID, Windows Hello or the device PIN)	Opens an exclusive signing link by email; email codes on every plan, and SMS, WhatsApp, ID and knowledge-based checks from Standard, paid in credits
What ties the signature to the document	Each signer's own cryptographic signature over the document's fingerprint and their entries	A certificate-based PDF signature, with a GlobalSign certificate in the US (QuoVadis in the EU)
Public blockchain	Every completed agreement and every signature anchored on Horizen, on every plan	Document hashes timestamped on Bitcoin through OpenTimestamps, on Enterprise
Checking a signed document	Anyone, free, with the open-source verifier inside every signed copy	In a PDF reader's Signatures panel
Prove a fact without the document	Yes: a zero-knowledge proof that you signed, and the date it was completed	Not offered
Free plan	2 documents, in total	5 envelopes a month, single user
Entry paid plan	Signing: $5 a month for 20 documents	Standard: $12 per user a month, or $10 per user a month billed annually, 25 envelopes per user a month

Privacy: "zero-knowledge architecture" and end-to-end encryption

Zoho's security page uses the phrase "zero-knowledge architecture". Under it, it lists what it does: documents are converted into PDFs and hashed, "Only the encrypted data gets transmitted and stored in our servers", data travels over SSL/TLS, "All data is encrypted with AES 256-bit encryption while at rest", and "Zoho employees cannot view users' data in plain text". Those are sound practices, with access controls on staff. What Zoho doesn't describe is who holds the keys, or a mechanism, such as encryption on your device, that keeps its own service from decrypting documents.

Attest's design removes the service from that question. Every document is encrypted in your browser with AES-256-GCM before upload, under a fresh key that is then locked separately to each party's own key. Documents are decrypted only in the parties' browsers, and Attest stores them only as ciphertext it can't read. We compared 21 e-signature services in October 2026, Attest and 20 others, and Attest was the only one that end-to-end encrypts every document, for every signer, by default.

Both use a blockchain, differently

Zoho Sign and Attest are among the few e-signature services we compared that use a public blockchain, so the difference is worth knowing.

• Zoho Sign timestamps signed documents on the Bitcoin blockchain through OpenTimestamps, on its Enterprise plan ($22 per user a month billed annually, as published on October 12, 2026). "Only the hash of the signed document will be added to the public blockchain network, not the document itself." An earlier Ethereum timestamping option "is no longer available", although old proofs can still be checked in the app.
• Attest anchors on Horizen on every plan, Free included. Each signature is anchored from the signer's own wallet, a blockchain account Attest creates and runs for each user; the completed agreement is anchored from the sender's; and the sealed copy's pages get their own anchor. Only fingerprints go on chain, never the document, its title or anyone's email address. Attest pays every network fee, so nobody holds or buys crypto.

Attest then adds what a timestamp alone doesn't give you: zero-knowledge proofs. A signer can prove they signed an agreement, and the date it was completed, without showing the document; each proof is verified on zkVerify. None of the other 20 services we compared mentions zero-knowledge proofs, and Zoho's "zero-knowledge architecture" describes who can access data, not proofs.

How signers sign

"No, signers do not need an account or a subscription to sign the documents you send them via Zoho Sign. Every envelope is sent to the signers in an email containing an exclusive signing link". The sender can add an email code on every plan, and from Standard, SMS or WhatsApp codes, government ID checks, knowledge-based authentication and Stripe Identity, which consume Zoho Sign credits at $0.10 each, as published on October 11, 2026.

On Attest, every signer approves with a passkey: a cryptographic key only the signer controls, unlocked with Face ID, Touch ID, Windows Hello or the device PIN. The passkey must confirm the signer was present and verified, and it signs a statement naming the exact document, by its fingerprint, and everything the signer entered. With most passkey providers, setting up takes one prompt, and signers never create an account or a password.

Proof that doesn't depend on the vendor

Zoho tells users to check a signed document in a PDF reader such as Adobe Acrobat Reader, in its Signatures panel. Its signing certificates come from GlobalSign in the US, Australia and Japan, QuoVadis in the EU and eMudhra in India, and paid plans add long-term validation. That check works without Zoho's service, and it shows the PDF hasn't changed since Zoho's certificate signed it.

An Attest signed copy carries more of the evidence inside the file: the signed pages, with a "Signed with Attest" stamp on each signature and a seal line at the foot of every page, a certificate of completion, the audit trail up to completion and a "Verify it yourself, without us" page, with the full evidence, the original document and a standalone verifier attached inside. Drop the PDF on that verifier in any browser: it checks each signer's passkey signature and entries, the original document against what every signer signed, Attest's anchored record of the agreement on Horizen, and that nothing was added after sealing, and it re-makes every page you see from what was signed and compares the result with the copy byte for byte. It needs no Attest service, only a public blockchain node.

Price at small volume

What you send	Attest	Zoho Sign (as published October 12, 2026)
A few documents	2 documents free, in total	Free: 5 envelopes a month, single user
Up to 20 a month	$5 a month	Standard: $12 per user a month, or $10 per user a month billed annually (up to 25 envelopes)
Per document, at 20 a month	25 cents	50 cents on annual billing, 60 cents month to month
Blockchain anchoring	Every plan	Enterprise: $28 per user a month, or $22 per user a month billed annually
Sending through an API	Pro: $49 a month, with 10,000 records a month	$0.50 per envelope, no commitment

Zoho Sign's prices are per user; extra checks, SMS, timestamps and qualified signatures use credits on top. Attest's plans are month to month, and the people who sign never pay on either service.

When Zoho Sign is the better fit

• Your business runs on Zoho. Zoho Sign connects with Zoho CRM, Books and other Zoho apps, and offers mobile and desktop apps.
• You need advanced or qualified signatures, through partner trust service providers (Swisscom from Standard; Uanataca, InfoCert and EU eIDs on Enterprise), or India's Aadhaar eSign and Singapore's Singpass.
• You need accredited timestamps. Zoho supports RFC 3161 timestamp authorities, with trusted timestamps from GlobalSign and Seiko and qualified timestamps from Uanataca.
• You need workflow features: unlimited templates (Professional), bulk send, SignForms for public signing, payment collection and 21 CFR Part 11 controls (Enterprise).
• You send a handful a month and want it free: Zoho's Free plan allows 5 envelopes a month.

Who should choose Attest

• Teams with confidential agreements, such as salary letters, term sheets and NDAs, who want a service that can't read them: every Attest document is end-to-end encrypted in the browser.
• Anyone who wants blockchain-backed proof on every document, not only on an enterprise plan, plus proofs that reveal nothing else.
• People who receive signed documents and want to check them free, with no account and no PDF reader setup.
• Small senders who want 20 documents a month for $5.

Starting on Attest

Sign in with your email and set up your signing key with a passkey and a recovery phrase. Upload a PDF (up to 8 MB), add up to 20 signers and place their fields: signature, initials, date signed, full name or text. Your first 2 documents are free, in total.