Secure distributed key management system

1. A distributed key management system, comprising

a) a server;

b) a plurality of key-holding computing devices adapted to communicate with the server, wherein each one of the plurality of key-holding computing devices is adapted to hold a different fragment of a private key; and

c) a key-requesting computing device adapted to communicate with the server to request the private key;

in response to the request for the private key, the server adapted to reconstruct the private key based on the fragments of the private key received from the plurality of key-holding computing devices,

wherein the server is configured to recalculate the private key based on the fragments of the private key when a new key-holding computing device joins the plurality of key-holding computing devices, and afterwards distribute the fragments of the private key to the plurality of key-holding computing devices and the new key-holding computing device and wherein the server is configured to remove one of the plurality of the key-holding computing devices from being able to communicate with the server when a predetermined number of other key-holding computing devices authorizes a removal;

the key-requesting computing device adapted to obtain the private key from the server, wherein the key-requesting computing device is adapted to produce a final key based on the private key received from the server such that the server has no access to the final key; and

the server is configured to conduct an operation related to the private key only when the server has been unlocked by any one of the plurality of key-holding computing devices using a same encryption key held on all of the plurality of key-holding computing devices, wherein the server is able to read a configuration file which is compulsory for conducting the operation only when server is unlocked.

2. The system of claim 1 , wherein the server is further adapted to reconstruct the private key based on the fragments received from at least a part of the plurality of key-holding computing devices.

3. The system of claim 2 , wherein the server is adapted to reconstruct the private key using Shamir's Secret Sharing algorithm over Galois Field 256.

4. The system of claim 3 , wherein the private key is a random number or is constructed using a random number, and the private key is a byte array with byte value in 0-255 range.

5. The system of claim 1 , wherein the plurality of key-holding computing devices are smartphones belonging to different users.

6. The system of claim 1 , wherein the server is locked when it has been restarted.

7. The system of claim 1 , wherein the operation is:

a) adding a new key-holding computing device;

b) removing one of the plurality of the key-holding computing devices;

c) generating a new private key; or

d) approving a request from the key-requesting computing device.

8. The system of claim 1 , wherein the key-holding computing devices are adapted to encrypt their respective fragments of the private key using a biometric authentication.

9. The system of claim 1 , wherein the server is adapted to hold the configuration file which is associated with a respective public key for each one of the plurality of key-holding computing devices; the server being unable to read the configuration file unless it is unlocked using the encryption key by any one of the plurality of key-holding computing devices using the encryption key held on all of the plurality of key-holding computing devices.

10. A method for distributively managing keys, comprising the steps of:

a) generating a private key by a server;

b) appointing a plurality of key-holding computing devices, wherein the appointing comprises registering a first one of the plurality of the key-holding computing devices using a PIN and registering rest of the plurality of the key-holding computing devices by approval of all or a predefined minimum number of plurality of existing key-holding computing devices;

c) splitting the private key into a plurality of fragments in accordance with a number of the key-holding computing devices and recalculating the privet key based on the plurality of fragments when a new key-holding computing device joins the plurality of key-holding computing devices and afterwards distributing the private key to the plurality of key-holding computing devices and the new key-holding computing device and wherein the server is configured to remove one of the plurality of the key-holding computing devices from being able to communicate with the server when a predetermined number of other key-holding computing devices authorizes a removal;

d) distributing a different one of the plurality of fragments to each one of the plurality of key-holding computing devices; and

the server is configured to conduct an operation related to the private key only when the server has been unlocked by any one of the plurality of key-holding computing devices using a same encryption key held on all of the plurality of key-holding computing devices; wherein the server is able to read a configuration file which is compulsory for conducting the operation only when server is unlocked.

11. The method of claim 10 , wherein the server is adapted to hold the configuration file which is associated with a respective public key for each one of the plurality of key-holding computing devices;

the server being unable to read the configuration file unless it is unlocked using the encryption key by any one of the plurality of key-holding computing devices using the encryption key held on all of the plurality of key-holding computing devices.