How to Manage Encryption at Rest in Snowflake

Why should I care about Snowflake encryption at rest?

Encryption at rest protects tables, stages, and backups from unauthorized disk access. Snowflake applies AES-256 automatically, so your data in Customers, Orders, and every other table is always encrypted without extra code.

How does Snowflakes key hierarchy work?

Snowflake maintains a three-level key hierarchy: the root key (in an HSM), account master key, and object keys for individual micro-partitions and stages.Each layer is encrypted by the one above it, limiting blast radius.

Can I rotate the account master key myself?

YesEnterprise Edition and higher allow manual rotation with ALTER ACCOUNT ROTATE MASTER KEY. Rotation creates a new key version and re-encrypts existing object keys in the background, with zero query downtime.

What SQL syntax controls encryption at rest?

The main DDL is ALTER ACCOUNT ROTATE MASTER KEY [ FORCE = TRUE ].You can view key metadata with SHOW PARAMETERS IN ACCOUNT LIKE 'MASTER_KEY'.

How do I confirm my data is encrypted?

Run SHOW DATABASES; and inspect the is_encrypted columnit should read TRUE. This confirms every tables micro-partition is protected.

Does encryption affect query performance?

No. Decryption happens in Snowflakes SSD cache before data reaches virtual warehouse memory, adding negligible latency.

Example: rotating keys in an ecommerce warehouse

The security team requests a quarterly key rotation. Execute ALTER ACCOUNT ROTATE MASTER KEY;.Queries like SELECT c.name, SUM(oi.quantity*p.price) FROM Customers c JOIN Orders o ... keep running uninterrupted.

Best practices for encryption at rest

Check your editions features. 2 Automate key-rotation reminders. 3 Enable Tri-Secret Secure if regulatory rules demand customer-managed keys. 4 Use SHOW ACCOUNTS to audit master_key_rotation_enabled.

What are common mistakes?

First, assuming you must encrypt columns manuallySnowflake already encrypts the physical files.Second, skipping key rotation policiessecurity auditors expect a documented schedule.

Further reading

See the Snowflake docs on Encryption and Key Management and Tri-Secret Secure for customer-managed options.

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