Pseudonymization

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Pseudonymization replaces detected values with deterministic vault tokens. It is reversible only when the caller has access to the vault. It is tokenization, not encryption: the vault retains the original values in memory or ETS until the caller clears or stops it.

{:ok, vault} = Obscura.Vault.Memory.start_link()

{:ok, result} =
  Obscura.redact("Email jane@example.com",
    entities: [:email],
    operators: %{email: %{type: :pseudonymize}},
    vault: vault
  )

result.text
#=> "Email <<EMAIL_001>>"

The same entity/value pair reuses the same token within one vault session:

Obscura.Vault.get_or_create(vault, :email, "jane@example.com")
#=> {:ok, "<<EMAIL_001>>"}

Token Format

Default tokens are ASCII and entity-scoped:

<<EMAIL_001>>
<<PHONE_001>>
<<CREDIT_CARD_001>>

Token formatting supports options such as :token_prefix, :token_suffix, :token_separator, :token_width, and :token_case.

The vault and token options are validated before any replacement starts. Missing or unavailable vaults and malformed token options return {:error, %Obscura.Anonymizer.Error{}} without including the source value.

Structured Data

Structured redaction can use pseudonymization because structured leaf strings flow through the anonymizer:

Obscura.redact(%{message: "Email jane@example.com"},
  entities: [:email],
  operators: %{email: %{type: :pseudonymize}},
  vault: vault
)