Computer-implemented systems and methods to enable complex functionality on a blockchain while preserving security-based restrictions on script size and opcode limits

Patent metadata

Field	Value
Publication number	US-11087322-B2
Application number	US-201716472174-A
Country	US
Kind code	B2
Filing date	Dec 15, 2017
Priority date	Dec 21, 2016
Publication date	Aug 10, 2021
Grant date	Aug 10, 2021

Abstract

The invention relates to blockchain technologies such as the Bitcoin blockchain. The invention uses a novel technique to decompose the functionality of a blockchain transaction script into several chunks or functional parts, and to use the output of a chunk as the input of the next chunk. Advantageously, this allows the blockchain to be used for ever complex tasks and computations while minimising script size, and also provides a novel architecture for the distributed execution of computational processes. The invention comprises a method of using a plurality of blockchain transactions to execute a computer-implemented task, comprising the steps: using an unlocking script (ULS 1 ) associated with a first input (In 1 ) in a blockchain transaction (Tx 2 ) to present at least one data item to a first locking script (LS 1 ) of another transaction (Tx 1 ) so as to provide a result on a stack; generating a further unlocking script (ULS 2 ) associated with a second input (In 2 ) and comprising the result from the stack; wherein the second input (In 2 ) is provided in a further blockchain transaction (Tx 3 ); and presenting the further unlocking script (ULS 2 ) to a further locking script (LS 2 ) such that the result from the stack is provided as input to the further locking script. Preferably, the locking script (LS 1 ) and further locking script (LS 2 ) are associated with outputs in different blockchain transactions.

First claim

The invention claimed is:

1. A system to use a plurality of blockchain transactions to execute a computer-implemented task, the system comprising: one or more processors; and
memory encoding instructions executable by the one or more processors to cause the system to perform operations comprising:
using an unlocking script (ULS 1 ) associated with a first input (In 1 ) in a blockchain transaction (Tx 2 ) to present at least one data item to a first locking script (LS 1 ) of another transaction (Tx 1 ) so as to provide a result on a stack;
generating a further unlocking script (ULS 2 ) associated with a second input (In 2 ) and comprising the result from the stack, wherein the second input (In 2 ) is provided in a further blockchain transaction (Tx 3 ), and wherein the locking script (LS 1 ) and further locking script (LS 2 ) are associated with outputs in different blockchain transactions; and
presenting the further unlocking script (ULS 2 ) to a further locking script (LS 2 ) such that the result from the stack is provided as input to the further locking script.

2. A system according to claim 1 wherein:
the unlocking script (ULS 1 ) and further unlocking script (ULS 2 ) are associated with inputs in different blockchain transactions.

3. A system according claim 1 wherein the operations further comprise:
using the at least one data item in the execution of a calculation or sequence of instructions provided within the first locking script (LS 1 ).

4. A system according to claim 1 wherein the operations further comprise:
using the result provided on the stack in the execution of a calculation or sequence of instructions provided within the further locking script (LS 2 ).

5. A system method according to claim 1 and further comprising the step of wherein the operations further comprise:
obtaining the result from the stack.

6. A system according to claim 1 wherein the operations further comprise:
using a blockchain client to obtain the result from the stack, wherein the blockchain client is a Bitcoin client.

7. A system according to claim 1 wherein the operations further comprise:
validating the blockchain transaction (Tx 2 ) and/or the other transaction (Tx 1 ), and/or further transaction (Tx 3 ) to generate the result on the stack.

8. A system according to claim 1 wherein the operations further comprise:
obtaining the result from the stack and inserting the result into an unlocking script after a return command or instruction.

9. A system according to claim 8 wherein the return command or instruction is a Bitcoin OP_RETURN opcode.

10. A system according to claim 1 wherein:
presenting the further unlocking script (ULS 2 ) to a further locking script (LS 2 ) provides a further result on the stack, or on a different stack.

11. A system according to claim 1 wherein the operations further comprise:
submitting the blockchain transaction (Tx 2 ) and/or other blockchain transaction (Tx 1 ) and/or further transaction (Tx 3 ) to a blockchain network.

12. A system according to claim 1 wherein:
the at least one data item is provided as metadata within the unlocking script (ULS 1 ); and/or
the result is provided as metadata within the further unlocking script (ULS 2 ).

13. A system according to claim 1 wherein the operations further comprise:
performing one or more of the steps of claim 1 more than once.

14. A system according to claim 1 wherein the plurality of blockchain transactions are for a blockchain, and wherein:
the blockchain is a consensus-based, distributed, electronic ledger; and/or
the blockchain is a Bitcoin blockchain; and/or
one, some or all of the plurality of blockchain transactions are Bitcoin transactions; and/or
the method is arranged for execution on the Bitcoin blockchain.

Assignees

• Nchain Licensing Ag

Inventors

• Vincent Stephane

Classifications

• G06F9/4484

  Executing subprograms · CPC title

• H04L9/3239 Primary

  involving non-keyed hash functions, e.g. modification detection codes [MDCs], MD5, SHA or RIPEMD · CPC title

• H04L9/50

  using hash chains, e.g. blockchains or hash trees · CPC title

• G06Q20/401 Primary

  Transaction verification · CPC title

• G06Q20/065

  using e-cash · CPC title