Blockchain secured by backward chained elements

A method to enhance blockchains by securing the blockchain using backward chained one-way elements and reducing the required number of steps for a calculation of a trusted block to a single hash operation the method, comprising:

• providing additional fields in a block where additional values are inserted before the block is hashed whereby the additional fields are used to build a cryptographic backward chain from the block to its previous block, and from this previous block to its previous block and so on, until a first genesis block is reached providing cryptographic security to detect manipulated chains;
• providing and using the back step generator as secured logic providing the required additional values;
• providing and using a non-secret cryptographic one-way function for building the additional values embedded in the back step generator and logically applied between adjacent blocks, such that the values of the previous block can be easily calculated from a current block in the chain;
• providing and using a secured storage to hold values used as initial secrets for the generation of the back step value and the back step seal value;
• providing and using a logic as part of the back step generator to calculate a seal from a hash value of the previous block and the current back step seal value in such a way that a backward calculation to the back step seal value is cryptographically hard;
• providing a logic inside the back step generator to pre-calculate back step and back step seal values at product initialization time by repeated application of the one-way functions to the initial secrets;
• providing and using a cache logic inside the back step generator that provides back step and back step seal values in time for the calculation of the block;
• providing and using a controller logic and a checkpoint address logic to store such pre-calculated values periodically after a defined number of steps in a secured non-volatile storage as checkpoint values and to fetch them back whenever the cache needs to be refilled;
• providing and using a cache controller to manage alternate refill and depletion of the two-cache storage blocks such that back step and back step seal values are immediately available whenever the next block needs to be hashed;
• providing and using a logic inside the back step generator that calculates the seal from the back step seal value and the previous block hash value such that a reverse calculation of the back step seal value is cryptographically hard;
• providing and using a logic to deliver the backstep seal value for a defined step of the chain to authorized people or institution for external verification of the correctness of the chain;
• providing a non-volatile secure storage inside the back step generator for secrets used to verify the authenticity of a seal value delivery request;
• providing a non-volatile secure storage for values used to protect the backstep seal value at delivery time;
• and further, providing and using a seal protection logic to protect the backstep seal value against unauthorized use;
• wherein the blockchain is secured by using backward chained one-way elements, and the number of steps for performing the calculation of a trusted block to a single hash operation are reduced.