# Replace the first n characters This function masks the first n characters, while the following ones remain as is. | Option | Description | | --- | --- | | Method | The Randomly method randomly selects a character. As a
result, two identical input values can be masked with different output values.

When
the same value appears twice in the input data, the
Consistently method ensures that the function outputs
the same masked value in the same Job execution.

This function can encrypt the output masked
values in the same format as the input values, using Format-Preserving Encryption (FPE)
methods:



The FPE methods are bijective methods, except when
using tweaks.

The FF1 with
AES and FF1 with SHA-2 methods
require a password to generate encrypted and repeatable masked values. Those FPE methods
do not use a seed.

You can specify this password in the Password or
256-bit key for FF1 methods field, from the Advanced
Settings of the component. | | Extra parameter | This function requires an extra parameter.

The extra parameter must be a number.
This is the number of characters to be masked.

You
can enter a second extra parameter, which is the replacement
character. | The following table shows examples of masked values depending on the input value, the method, and the extra parameter. | Input value | Method | Extra parameter | Example of a masked value | Details | | --- | --- | --- | --- | --- | | Jack | Randomly | "2" | Pvck | The first two characters from the input values are masked.

The replacement
character is not defined. The first two characters are masked with random
characters | | S1000D | Randomly | "2,s" | ss000D | The first two characters from the input values are masked.

The first two
characters are masked with the defined character. |