Frequently asked questions about sproof, digital documents and blockchain.
In sproof, each change of your profile is represented by an event. Multiple events can then be embedded into a single transaction. In order to submit your events to the blockchain you need to digitally sign them with your private key. Therefore, you need to enter your passphrase before your events can be sent to the blockchain. Once the transaction is submitted, it will take up to 10 minutes before your changes are available in sproof.
sproof can be built on top of any blockchain. The public version of sproof uses the public Ethereum blockchain.
In sproof, you can choose where you want to store your private key. There are two options:
- On the sproof server: We securely store your private key for you. For that, we encrypt your private key with a passphrase of your choice.
- On your own computer: You can download your private key from our web app. You can create your private key also locally on your device and only store your public key on our servers. We then have no access to your private key.
The sproof explorer shows all information which is publicly stored on the blockchain and in ipfs. The explorer can be used to view all sproof profiles, documents, transactions and events. Additionally, the explorer provides the functionality to verify if a document, e.g., a PDF file issued via the sproof network.
The password is used to secure your sproof account. We do not store passwords in plaintext, but we can send you a link to reset your password. In order to commit transactions to the blockchain you need a private key. This key is stored encrypted and protected by your passphrase. sproof is never in possession of your passphrase and has no access to your private key. If you forget your passphrase we can not reset it for you and you can only create a new passphrase by knowing the old one. The sproof-code is a synonym for mnemonic and is used to generate your private key.
An event represents a single action of a sproof profile. Each sproof profile needs at least one event: the profile create event. For each additional step, e.g, profile update, document registration or revokation, an additional event is created. To increase the performance and to reduce costs we register multiple events within a single blockchain transaction, which is signed by the private key of the profile.
A Web of Trust (WoT) is a network of confirmations. Each member of a WoT is allowed to confirm each other user. This means for sproof, that each profile can confirm all other profiles. You can confirm profiles of entities you know and trust. Similarly, the strength of your profile increases if you collect confirmations from other profiles.
In sproof we link the public key of a user to a profile. A profile consists of a name, image and a description. It is also possible to add and confirm a website. Additionally, a profile can collect confirmation from other profiles to build a Web of Trust.
A private key is needed to create digital signatures, encrypt or decrypt data. There always exist a cryptographically linked public key to a private key. For blockchain applications, e.g., sproof, the private key is your secret to add or update your data. If you lose your private key, you do not have access anymore. The private key can be encrpyted with a passphrase.
A passphrase is a password which protects your private key. You can only change your passphrase if you know the old one. If you forgot your passphrase we can not reset it for you. This is to protect your private key from unauthorized access.
A nonce is a random number which should only be used once in cryptographic operations.
A mnemonic is a sentence or a collection of words. In sproof we use menemonic to generate your private key.
A document can be any file in any format. Most commonly, documents are PDF files.
A blockchain is a decentralized, append-only database. Blockchains group transactions into blocks and use cryptographic building blocks such as public and private keys and hash functions. sproof uses a blockchain to immutably store hash references to information about your profile and registered or revoked documents.
In case your private key gets leaked, you have two options. First, you can revoke your profile and create a new one including a new private key. Second, if you registered an offline (cold storage) private key to your profile you can update your online private key with the offline key.
If you loose or forget your private key, we have no way to recover your profile. You are the only one, who has access to it. In the settings page you can create a new key.
No. We use the power of already established public blockchains.
It is easy to integrate sproof in existing applications. Please follow our guide on the developers site to learn more about the integration.
Short answer. No, you can’t.
Long answer: Blockchains are append-only databases. Once a transaction has become part of the blockchain it is practically impossible to delete that data. sproof only stores hash references in the blockchain and without the original data it is impossible to learn anything about the document. However, you may choose to store documents publicly. In this case, it is not possible to delete these documents. You may revoke documents, but that only adds a flag in that documents history without changing the original entry.