Introduction
Traditional data security measures—such as passwords, firewalls, and encryption—focus on preventing unauthorized access to company systems and data stores. However, these methods fall short in protecting critical assets (e.g., contracts, property titles, account statements) from being altered or deleted by individuals who gain access legitimately or through hacking.
Blockchain technology offers an additional layer of security by ensuring data immutability and integrity, even when conventional security measures are breached.
Understanding Blockchain in Data Management
At its core, blockchain is a decentralized ledger technology known for enabling peer-to-peer applications with consensus-based data changes. While adopting blockchain traditionally requires specialized infrastructure and development practices, Oracle has simplified its integration by embedding blockchain capabilities directly into its database.
Key Components of Blockchain Technology
- Immutability: Ensures data cannot be altered or deleted after insertion.
- Cryptographic Digests: Unique hash values generated for each data row.
- Cryptographic Signatures: End-user verification using private keys.
- Distributed Systems: Decentralized validation to prevent single-point tampering.
By incorporating these components into the Oracle Database, businesses can leverage blockchain’s security benefits without overhauling existing applications.
Oracle’s Blockchain Implementation
Immutable Tables
Introduced in Oracle Database 21c (21.3), immutable tables allow only insert operations. Key features include:
- No updates or deletes permitted—even by administrators (
SYSDBA). - Schema definitions remain fixed.
- Compatible with relational data, JSON documents, indexing, and partitioning.
👉 Explore how immutable tables enhance data security
Blockchain Tables
Designed to counter hacker-related tampering, blockchain tables:
- Organize rows into cryptographically linked chains.
- Automatically generate hash values for each row based on its data and the preceding row’s hash.
- Include timestamps for auditability.
Verification is performed using the DBMS_BLOCKCHAIN_TABLE.VERIFY_ROWS procedure:
DECLARE
actual_rows NUMBER;
verified_rows NUMBER;
BEGIN
SELECT COUNT(*) INTO actual_rows FROM admin.my_bc_tab;
dbms_blockchain_table.verify_rows(
schema_name => 'admin',
table_name => 'MY_BC_TAB',
number_of_rows_verified => verified_rows);
DBMS_OUTPUT.put_line('Actual_rows='||actual_rows|| ' Verified Rows=' || verified_rows);
END;
/End-User Data Signing
To prevent false data insertion via stolen credentials:
- Users cryptographically sign data with a private key.
- Public keys are registered in the database for validation.
- Oracle can countersign inserts, providing a crypto-receipt to confirm data recording.
Cryptographic Digest Distribution
To detect large-scale cover-ups (e.g., entire database replacement):
- Schema owners periodically publish cryptographic digests.
- Digests can be stored on public blockchains (e.g., Ethereum), emailed, or shared via REST APIs.
👉 Learn more about Oracle’s anti-tampering measures
Getting Started with Oracle Blockchain
- No additional cost: Immutable and blockchain tables are free features in Oracle Database.
- Backward compatibility: Available in Oracle Database 19c (19.10+) via patches.
Resources:
FAQ
Q: Can blockchain tables replace traditional databases?
A: No—they complement existing databases by adding tamper-proofing for critical data.
Q: How does Oracle ensure private keys aren’t exposed?
A: Private keys never leave the user’s device; only public keys are shared with the database.
Q: Are there performance trade-offs with blockchain tables?
A: Minimal overhead due to Oracle’s optimized implementation.
Q: Can I migrate existing tables to blockchain tables?
A: Yes, but the process requires creating a new blockchain table and migrating data.
Q: Is blockchain suitable for all data types?
A: Best for high-value, low-frequency data (e.g., contracts, audit logs).