2018年-数据局_区块链系列报告三_8页_141kb

Pascal Coin: A Cryptocurrency Without Need of Historical Operations

Core Content

PascalCoin is a cryptographic virtual currency that introduces a novel approach to transaction verification and account management by using account numbers instead of public keys as in Bitcoin. This design allows for more efficient and simpler operations, as it eliminates the need to track historical transactions to validate a transfer.

Main Points

Definition

• PascalCoin uses account numbers for transactions rather than Bitcoin’s public keys.
• Each account number is associated with a unique PIN (cryptographic key), which can be changed at any time.
• A PIN can be used for multiple accounts, but each account has only one valid PIN.

Introduction

• PascalCoin is a variant of cryptographic currency inspired by Bitcoin.
• It is recommended to have technical knowledge of Bitcoin to understand the concepts presented.

History

• Bitcoin introduced blockchain and mining as foundational elements.
• Blockchain stores historical transactions in a Merkle Tree to prevent double-spending.
• Mining ensures block consistency and generates new currency.

Key Differences from Bitcoin

• Account numbers are used instead of public keys, making them easier to handle and more similar to traditional bank accounts.
• Transactions do not require referencing previous transactions, only the current balance of the account.
• Public keys are always known, enabling secure message encryption.
• No need to store all historical transactions for verification, improving efficiency and reducing storage requirements.

Key Features

Safe Box

• A centralized storage for account balances.
• Contains checksums to ensure integrity of the data.
• The Safe Box Hash is the hash of all Block Hashes, ensuring the state of the safe box is consistent and tamper-proof.

Block Chain

• Similar to Bitcoin, but includes Safe Box Hash to indicate the state of the safe box before applying operations.
• Each block includes:
  • Block number
  • Account keys
  • Reward and fee
  • Timestamp
  • Compact target and nonce
  • Old Safe Box Hash
  • Operations Hash (Merkle Tree hash)
  • Proof of Work

Account Structure

• Each account includes:
  • Account number (32-bit unsigned)
  • Public EC Key (variable size, up to 200 bytes)
  • Balance (64-bit unsigned)
  • Updated block (32-bit unsigned)
  • N Operation (32-bit unsigned, used to prevent duplicate operations)

Operations

• PascalCoin supports basic operations:
  • Transaction from 1 to 1
  • Change key
  • Recover money from an unoperative account
• Future protocol upgrades may introduce new types of operations.

Advantages

• Faster transaction verification due to direct balance access.
• More efficient use of disk space for miners.
• Support for multiple cryptographic keys improves security.
• Message encryption using public keys allows for secure communication.
• No need to store all historical transactions for each account.

Disadvantages

• Limited account numbers due to fixed production, unlike Bitcoin’s unlimited address space.
• Increasing block size and checksum calculation costs over time, making it less efficient than Bitcoin.

Security Guarantee

• Safe Box integrity is ensured by:
  • Calculating the Block Hash for each "Block Account".
  • Generating the Safe Box Hash from all Block Hashes.
  • Ensuring the Safe Box Hash is unique and cannot be manipulated.
• Block Chain includes the Safe Box Hash to prevent tampering and ensure consistency.
• Duplicate operations are controlled using the n_operation field, ensuring each transaction has a unique sequence number.

Conclusion

PascalCoin offers a simpler and more efficient approach to managing cryptographic currency by using account numbers and a centralized Safe Box. This design allows for direct balance checks, secure message encryption, and protocol upgrades. However, it comes with trade-offs such as limited account numbers and increased computational costs over time.