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Argon2 password hashing parameters

Ory Kratos supports password hashing using Argon2 in the Argon2id variant. It's important to set up it's parameters to ensure a stable and reliable operation of Ory Kratos. In essence, you want to fulfill the following constrains:

  1. Duration: the execution time of one hashing operation - this translates to the response time of Ory Kratos on login and registration.
  2. Memory: the amount of available memory on the server
  3. Space: the amount of space for persistent storage

We recommend choosing a duration of 0.5s to 1s and as much memory as possible. To determine the exact recommended values following security best practices, run the CLI helper included in Ory Kratos:

kratos hashers argon2 calibrate 1s

It will output the exact values to use in the configuration.

Head to our blogpost about Argon2 parameters to learn how this command and password checking in Ory Kratos works.

If you encounter any problems like timeouts or out-of-memory errors, consolidate our troubleshooting guide.