Methods and systems for digital identification and certification

1 . A system for issuing reusable certificates of unique association between a public key and a physical person, wherein no more than one public key is associated with the same person, the system comprising a central authority database server and one or more certifying entities, the central authority database server comprising a user database storing a record for each of a plurality of users, each user being a physical person, each record comprising an internal identifier for the respective physical person and a public key associated with the respective physical person, wherein:

the certifying entities are configured to receive, from a first user, a public key together with a request for a certificate of unique association with the public key, the first user being a physical person;

the certifying entities are configured to verify one or more identification documents of the first user, and to communicate to the central authority a plaintext or a cryptographic hash of identifying attributes of the first user together with the public key; and the central authority database server is configured to determine whether the plaintext or cryptographic hash is already associated with another public key,

wherein, if the plaintext or cryptographic hash is found to be not already associated with another public key:

the central authority database server is configured to store the plaintext or cryptographic hash and the public key in the user database; and

the certifying entity and/or the central authority are configured to issue a reusable certificate of unique association between the public key and the first user.

2 . The system of claim 1 , wherein the identification documents are official documents.

3 . The system of claim 1 , wherein the central authority database server and the one or more certifying entities are operated independently from each other.

4 . The system of claim 1 , wherein the cryptographic hash is a cryptographic public key or a hash of a public key associated with the first user's identity.

5 . The system of claim 1 , wherein, if the plaintext or cryptographic hash is found to be already associated with another public key, the first user's request is rejected.

6 . The system of claim 1 , wherein, upon a request from the first user or one of the certifying entities for a revocation of the first user's identity, the central authority database server is configured to update the first user's record to indicate that the first user's identity was revoked.

7 . The system of claim 1 , wherein, upon a request from the first user for a revocation of the first user's key, the central authority is configured to update the first user's record to indicate that the first user's key was revoked.

8 . A system for issuing reusable certificates of key uniqueness, the system comprising a central authority database server and one or more certifying entities, the central authority database server comprising a user database storing a record for each of a plurality of users, each record comprising an internal identifier for the respective user across all certifying entities, wherein:

the certifying entities are configured to verify, upon a request from a first user for a uniqueness certificate, one or more identification documents of the first user, and to communicate to the central authority a plaintext or a cryptographic hash of identifying attributes of the first user; and

the central authority database server is configured to store the plaintext or cryptographic hash in the user database as a unique internal identifier for the first user and to determine whether the plaintext or cryptographic hash is unique,

wherein, if the plaintext or cryptographic hash is found to be unique, the certifying entity and/or the central authority are configured to issue a reusable certificate of global uniqueness for the first user, the certificate being associated with a user public key,

wherein, upon receiving a request for the creation of a uniqueness context ID

from a context owner, the central authority database server is configured:

to create the uniqueness context ID and to return it to the context owner;

to receive a message from the first user, the message being signed using a globally unique public key of the first user, comprising the uniqueness context ID; and

to create a context dependent uniqueness certificate and to send it to the first user, wherein the context dependent uniqueness certificate is configured to be used for verifying uniqueness within the context identified by the context ID without revealing the user's globally unique public key.

9 . The system of claim 8 , wherein a user-friendly string name is associated with the uniqueness context ID.

10 . A system for associating an attestation of experience to a public cryptographic key, the system comprising one or more certifying entities, each certifying entity being configured

to receive a request from a first user for certification of a claim together with evidence supporting the claim and a public cryptographic key of the first user, the first user's claim being related to a first user's experience, wherein the certifying entities are configured to verify an association between the first user and the public cryptographic key of the first user, wherein the certifying entities are configured to verify the association between the first user and the public cryptographic key of the first user based on a reusable certificate of unique association between the public key and the first user,

to verify validity, relevance and completeness of the supporting evidence regarding the first user's claim, and

to issue a cryptographically signed certificate in the form of text comprising the claim and the public cryptographic key of the first user, wherein the certificate comprises no information that allows identifying the first user.

11 . The system of claim 10 , comprising a central authority creating standards and policies to be followed by all certifying entities of the system, to regulate the activity of the certifying entities and/or supply them with information systems, maintenance and support services.

12 . The system of claim 10 , wherein the evidence comprises at least one of academic diplomas issued by an academic institution to the first user or professional certificates issued by a professional certifying institution to the first user.

13 . The system of claim 10 , comprising a central authority database server comprising a user database storing a record for each of a plurality of users, wherein, upon a request from the first user or one of the certifying entities for a revocation of the issued certificate, the central authority database server is configured to update the first user's record to indicate that the issued certificate has been revoked, wherein any requests to the central database authority regarding the validity of the issued certificate would indicate that it has been revoked.

14 . The system of claim 10 , wherein the first user's experience comprises at least one of an age of the first user and an employment status of the first user.

15 . The system of claim 10 , wherein the first user's experience comprises at least one of a professional certification held by the first user and a diploma issued to the first user.

16 . The system of claim 10 , wherein the first user's experience comprises work experience of the first user.

17 . The system of claim 10 , comprising a central authority database server comprising a user database storing a record for each of a plurality of users, the record comprising the certificate of unique association between the public key and the first user.