Question 1

What is Qpher?

Accepted Answer

Qpher keeps your documents under your rules after they leave your hands: Qpher Vault, Qpher Legacy and Qpher API share one engine.

Question 2

What is Qpher Vault?

Accepted Answer

Qpher Vault is an iPhone app that encrypts your documents on your device, signs them in your name and shares them only with the people you choose.

Question 3

What devices are supported?

Accepted Answer

Qpher Vault runs on iPhone with iOS 17 or later, and in the browser at vault.qpher.ai.

Question 4

Do I need technical knowledge to use Qpher Vault?

Accepted Answer

Not at all. Qpher Vault is designed for non-technical users. Simply download the app, create an account, and you can encrypt your first document in under 60 seconds. The complex cryptography happens behind the scenes.

Question 5

What file types can I encrypt?

Accepted Answer

PDF, Word, Excel, images and most other files you can share from your iPhone, up to your plan's file-size limit.

Question 6

What encryption algorithms does Qpher Vault use?

Accepted Answer

Qpher Vault uses ML-KEM-768 (FIPS 203) for key encapsulation and AES-256-GCM for symmetric encryption. For maximum security, we use X-Wing hybrid mode which combines classical X25519 with ML-KEM-768, protecting against both classical and quantum attacks.

Question 7

Where are my encryption keys stored?

Accepted Answer

Private keys are generated and used only inside Qpher's isolated key service and are never exported. On your iPhone, you can lock the app with Face ID.

Question 8

Can Qpher access my encrypted documents?

Accepted Answer

Not in normal operation. Qpher Vault uses client-side encryption: your documents are encrypted on your device before being uploaded, and Qpher does not read your document contents during normal service operation — decryption also happens on your device. Each file's encryption key is unwrapped inside Qpher's access-controlled key-management service only when you request it. For the full trust model, including what this means for legal requests, see Section 6.5 of our Privacy Policy at qpher.ai/legal/privacy.

Question 9

Is Qpher zero-knowledge?

Accepted Answer

Qpher is not zero-knowledge. Private keys are generated and used only inside an isolated key service and are never exported; on client-side paths (Vault, Organization send, .qpher) Qpher never sees the plaintext; the API's server-side mode receives plaintext over TLS, processes it in memory and does not store it.

Question 10

What happens if I forget my password?

Accepted Answer

You can reset your password through the app using your registered email address. Your encrypted documents remain safe — the encryption keys are tied to your account, not your password.

Question 11

How do I share encrypted documents?

Accepted Answer

Open the document, tap Share, enter the recipient's email address and choose view-only or download. They open it in the browser with a code sent to their email.

Question 12

What is the difference between view-only and download permission?

Accepted Answer

View-only: they read it in Qpher Vault, which doesn't let them save or export it, under a watermark of their email and the date. Download: they can save it.

Question 13

Can I share documents with people who don't have Qpher Vault?

Accepted Answer

Yes. They get an invitation to install Qpher Vault; once they register and verify the email you shared to, the document is available to them.

Question 14

Can I revoke access to a shared document?

Accepted Answer

Yes. Revoke the share and the recipient can no longer open it. A copy they already saved stays with them.

Question 15

Is Qpher Vault free to use?

Accepted Answer

Yes. The Free plan lets you encrypt, share and receive documents within monthly limits; Personal raises them. Plans and prices are shown in the app.

Question 16

How do I upgrade my plan?

Accepted Answer

Open Settings, tap Plan & billing and choose a plan. Upgrades go through Apple In-App Purchase and take effect immediately.

Question 17

Can I cancel my subscription?

Accepted Answer

Yes, in iOS Settings → Subscriptions. Personal stays active until the end of the paid period. Cancelling never deletes your documents.

Question 18

Do you offer business or enterprise plans?

Accepted Answer

Yes: Qpher Vault Organization edition, set up by an admin in Qpher Portal. See qpher.ai/product or write to sales@qpher.ai.

Question 19

What is post-quantum cryptography?

Accepted Answer

Post-quantum cryptography (PQC) uses mathematical algorithms that are resistant to attacks from quantum computers. Traditional encryption (RSA, ECC) will be broken when large-scale quantum computers become available. PQC algorithms like ML-KEM-768 and ML-DSA-65 are designed to remain secure even against quantum attacks.

Question 20

Is my data safe if I lose my phone?

Accepted Answer

Documents are encrypted before upload, and their keys are held by Qpher's isolated key service. Sign in on a new iPhone to get them back.

Question 21

Does Qpher Vault prevent screenshots?

Accepted Answer

It can't stop them. It detects screenshots and logs them against the document, and covers the document while the screen is being recorded.

Question 22

How does the watermark feature work?

Accepted Answer

When a document is shared with view-only permission, the recipient's email address is displayed as a visible watermark across the document. This discourages unauthorized distribution by making it traceable to the specific recipient.

Question 23

How do I invite team members to my organization?

Accepted Answer

Invite colleagues from Qpher Portal; they sign in to Qpher Vault on iPhone. Sharing inside the organization needs no key re-wrap.

Question 24

What plan do I need for team features?

Accepted Answer

Team features need Qpher Vault Organization edition, a paid plan an admin sets up in Qpher Portal. Personal accounts are for one person.

Question 25

Can I manage team members' access?

Accepted Answer

Yes. Organization owners and admins can invite members, suspend access immediately, and remove members permanently. Suspended members instantly lose access to all shared documents and encryption keys.

Question 26

What happens when a team member leaves the organization?

Accepted Answer

Removing a member revokes their access to the organization's documents immediately.

Question 27

Why can't I decrypt a document?

Accepted Answer

Check you're signed in with the right account, that your organization membership is active, and that the share wasn't revoked. Still stuck? support@qpher.ai

Question 28

Why is my shared document showing as 'pending'?

Accepted Answer

Pending means the recipient hasn't opened it yet. It becomes available once they open the link we emailed them, or sign up for Qpher Vault with that address.

Question 29

How do I restore my account on a new device?

Accepted Answer

Install Qpher Vault on the new iPhone and sign in with the same account. Your documents and shares come back; your keys are held by Qpher's key service.

Question 30

Face ID is not working with Qpher Vault. What should I do?

Accepted Answer

Check Face ID is set up in iPhone Settings → Face ID & Passcode, then in Qpher Vault open Settings → Autolock & MFA and turn on Use Face ID.

Question 31

How do I get started with the Qpher API?

Accepted Answer

Sign up at portal.qpher.ai, name your organization and generate a free API key. The quickstart is at docs.qpher.ai.

Question 32

What programming languages are supported?

Accepted Answer

Official SDKs for Python, Node.js and Go. Any language that speaks HTTP and JSON can call the REST API directly.

Question 33

What is the difference between Qpher API and Qpher Vault?

Accepted Answer

Qpher API is for developers who build encryption and signing into their own systems. Qpher Vault is the app people use to encrypt, sign and share documents.

Question 34

How is Qpher different from Cloud KMS?

Accepted Answer

Google Cloud KMS and AWS KMS ship post-quantum key operations. They give you primitives — key encapsulation and signing. Qpher gives you the hand-off: encrypt on your device, sign in your name, deliver to someone outside your organization, and prove it later.

Question 35

What PQC algorithms does the API support?

Accepted Answer

ML-KEM-768/1024 (FIPS 203), ML-DSA-65/87 (FIPS 204), SLH-DSA (FIPS 205), hybrid X-Wing and composite ECDSA P-256 + ML-DSA-65. Some need a paid plan.

Question 36

How does key management work?

Accepted Answer

Generate, rotate and retire keys through the API; archive them, irreversibly, in Qpher Portal only. Private keys are used only inside the isolated key service.

Question 37

What is the key_version parameter?

Accepted Answer

Encrypt and sign may omit key_version: Qpher uses the active key and returns its version. Decrypt, verify, encapsulate and key wrap always need it.

Question 38

What API plans are available?

Accepted Answer

Current plans and prices are on qpher.ai/plans.

Question 39

How is API usage metered?

Accepted Answer

Each encrypt, decrypt, sign or verify call counts toward your plan's monthly usage. Limits are on qpher.ai/plans.

Question 40

Is Qpher SOC 2 compliant?

Accepted Answer

Not yet: no SOC 2 audit has been completed. The Trust Center at qpher.ai/trust describes our security practices, data handling and incident response.

Question 41

How does tenant isolation work?

Accepted Answer

Each customer gets a separate tenant, isolated at four layers: repository filtering, database constraints, request context and gateway enforcement.

Question 42

What happens if the API is unavailable?

Accepted Answer

Qpher API fails closed: if the policy engine cannot be reached, API requests are denied rather than allowed. The SLA is at qpher.ai/legal/sla.

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