Class CryptoReplaceFfxFpeConfig (0.15.2)

Replaces an identifier with a surrogate using Format Preserving Encryption (FPE) with the FFX mode of operation; however when used in the ReidentifyContent API method, it serves the opposite function by reversing the surrogate back into the original identifier. The identifier must be encoded as ASCII. For a given crypto key and context, the same identifier will be replaced with the same surrogate. Identifiers must be at least two characters long. In the case that the identifier is the empty string, it will be skipped. See https://cloud.google.com/dlp/docs/pseudonymization to learn more.

Note: We recommend using CryptoDeterministicConfig for all use cases which do not require preserving the input alphabet space and size, plus warrant referential integrity.

The ‘tweak’, a context may be used for higher security since the same identifier in two different contexts won’t be given the same surrogate. If the context is not set, a default tweak will be used. If the context is set but: 1. there is no record present when transforming a given value or 2. the field is not present when transforming a given value, a default tweak will be used. Note that case (1) is expected when an InfoTypeTransformation is applied to both structured and non-structured ContentItem\ s. Currently, the referenced field may be of value type integer or string. The tweak is constructed as a sequence of bytes in big endian byte order such that: - a 64 bit integer is encoded followed by a single byte of value 1 - a string is encoded in UTF-8 format followed by a single byte of value 2

Common alphabets.

The native way to select the alphabet. Must be in the range [2, 95].