Patent AU-2019101343-A4 (AU)
Title: A computer system implemented method for generating a symmetric encryption key for encrypting and decrypting secure data
Inventor: ANSON MARK RODNEY
IPC: H04L9/14
Filed: 2019-11-05
Granted: 2019-12-12
Abstract: ACOMPUTERSYSTEMIMPLEMENTEDMETHODFOR GENERATING A SYMMETRIC ENCRYPTION KEY FOR ENCRYPTING AND DECRYPTING SECURE DATA Methods and apparatus implemented in a computer system, the methods and apparatus producing a symmetric encryption key termed a Cipherkey produced for protecting a computer system user's hidden data from unauthorised access by an intruder. The methods and apparatus receive a first input item being a user supplied secret termed the Secret, and a second input item termed Encrypted Random Data which is a sufficiently large mass of encrypted data bytes. The Secret can be a password comprised of alphanumeric text, a geometric shape input, biometric data, or more generally any item of unchanging information only known by or more generally insertable only by the valid user of a computer system. The second input item Encrypted Random Data shall be the encrypted transformation of a sufficiently large block of pseudo-random text, a big block of encrypted data stored and preserved in computer storage. After receiving a first input item, a Secret, a computer system performs a precise method of computation based on this input. In a first step the Secret is hashed in three different ways using three different one-way cryptographic hashing algorithms such as SHA-256, SHA-384 and SHA-512 so as to compute three different hash values identified by the terms Hash1, Hash2 and Hash3. In a second step, one of those three different hash values, Hash2, is transformed into a string of text that can be used as a file name identifier or signifier. In the third step, a computer system takes the file name identifier and searches a computer storage to find data with the corresponding file name. If corresponding data is found, a computer system will read the stored data corresponding to the file name and store this input in the memory of a computer system. This data found in storage in the third step is the second input item, the Encrypted Random Data. In a fourth step, the Encrypted Random Data is decrypted using the third hash value as a decryption key, the Hash3 value. The decrypted result of the fourth step is termed a Random Data object. In the fifth step, a computer system joins the bytes of data of the Hash1 value and the decrypted Random Data bytes into a single item of data called a Cipherkey source material. In the sixth step, this Cipherkey source material is hashed with a one-way cryptographic hashing algorithm to output a hash value result termed a Cipherkey, a hash value that can be used a symmetric encryption key for protecting a computer system user's hidden data. OBTAIN USERS SECRET PASSWORD 103 APPLY AT LEAST ONE HASHING ALGORITHM TO HASH THE USERS SECRET PASSWORD AT LEAST ONE TIME CREATING AT LEAST 105 A FIRST HASH VALUE TERMED THE HASH1 PRODUCE A RANDOM DATA 107 ENCRYPTED AND DECRYPTED WITH HASHl PRODUCE CIPHERKEY SOURCE MATERIAL 109 CIPHERKEY SOURCE MATERIAL 111 HASHi VALUE DERIVED FROM USER'S PASSWORD 113 RANDOM DATA 115 APPLY HASHING ALGORITHM TO THE CIPHERKEY SOURCE MATERIAL 117 CREATING A SYMMETRIC KEY TERMED THE CIPHERKEY CIPHERKEY 119 USE CIPHERKEY TO DECRYPT A CONFIGURATION DATA FOR THE USER + 121 USER CONFIGURATION DATA 123 PROVIDE CRYPTOGRAPHIC FUNCTIONS TO THE USER 125