Technique for split knowledge backup and recovery of a cryptographic key
First Claim
1. A method for storing and retrieving a cryptographic private key, comprising:
- calculating a one-way hash value of an initial cryptographic private key;
generating a plurality of key segments, at least a first of the plurality of key segments being a random number, and at least a second of the plurality of key segments being a combination of the random number and a portion of the initial cryptographic private key;
distributing each of the plurality of key segments to one of a plurality of trusted users; and
when the cryptographic private key is to be recovered;
receiving the plurality of key segments from the plurality of trusted users;
generating a recovered key from the plurality of key segments;
calculating a one-way hash value of the recovered key;
comparing the hash value of the recovered key to the hash value of the initial cryptographic private key; and
if the hash value of the recovered key is the same as the hash value of the initial cryptographic private key, using the recovered key as the private key in a cryptographic communication system.
1 Assignment
0 Petitions
Accused Products
Abstract
In a secure cryptographic environment, a private key in a private/public key cryptographic scheme needs to be backed up and recovered in case of a loss or corruption of the private key. To back up the private key, multiple key segments are generated based on the private key which are distributed to a corresponding number of trusted individuals, each of whom has knowledge of only his or her key segment. The key can be restored only when all of the trusted individuals provide the respective key segments, based on which the original private key is reconstructed. In addition, each trusted individual is uniquely identifiable by a personal identification number. Advantageously, the private key which is secret can be backed up and restored without any individual having knowledge of the full key.
-
Citations
18 Claims
-
1. A method for storing and retrieving a cryptographic private key, comprising:
-
calculating a one-way hash value of an initial cryptographic private key;
generating a plurality of key segments, at least a first of the plurality of key segments being a random number, and at least a second of the plurality of key segments being a combination of the random number and a portion of the initial cryptographic private key;
distributing each of the plurality of key segments to one of a plurality of trusted users; and
when the cryptographic private key is to be recovered;
receiving the plurality of key segments from the plurality of trusted users;
generating a recovered key from the plurality of key segments;
calculating a one-way hash value of the recovered key;
comparing the hash value of the recovered key to the hash value of the initial cryptographic private key; and
if the hash value of the recovered key is the same as the hash value of the initial cryptographic private key, using the recovered key as the private key in a cryptographic communication system. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. A method for storing a cryptographic private key, comprising:
-
generating a plurality of key segments, at least a first of the plurality of key segments being a random number, and at least a second of the plurality of key segments being a combination of the random number and a portion of an initial cryptographic private key; and
distributing each of the plurality of key segments to one of a plurality of trusted users. - View Dependent Claims (10, 11, 12)
-
-
13. A method for retrieving a cryptographic private key, comprising:
-
receiving a plurality of key segments from a plurality of trusted users, at least a first of the plurality of key segments being a random number, and at least a second of the plurality of key segments being a combination of the random number and a portion of an initial cryptographic private key; and
generating a recovered key from the plurality of key segments. - View Dependent Claims (14, 15, 16, 17, 18)
-
Specification