d2-hasher 1.0.0

Multilayer SHA-512 hashing utility for PII columns in CSV/TXT files

d2-hasher

Multilayer SHA-512 hashing utility for PII columns in CSV/TXT files.

Installation

pip install d2-hasher

Quick Start

Python API

from d2_hasher import hash_columns

# Hash columns in a CSV file
hash_columns(
    input_file="data.csv",
    columns=["national_id", "name"],
    secret_salts=["your_secret_salt_1", "your_secret_salt_2"],
)
# Output written to data_hashed.csv

# Hash a DataFrame in-memory
import pandas as pd
df = pd.read_csv("data.csv")
result = hash_columns(
    df=df,
    columns=["national_id", "name"],
    secret_salts=["your_secret_salt_1", "your_secret_salt_2"],
)

Command Line

d2-hasher \
  --input-file data.csv \
  --columns national_id name \
  --secret-salts "your_secret_salt_1" "your_secret_salt_2" \
  --output data_hashed.csv \
  --chunksize 50000

hash_columns() Parameters

Parameter	Type	Required	Default	Description
columns	list[str]	Yes	—	Column names to hash
secret_salts	list[str]	Yes	—	Secret salts applied in order
input_file	str	No*	—	Path to CSV/TXT file
df	DataFrame	No*	—	In-memory DataFrame
output	str	No	<stem>_hashed.csv	Output file path
chunksize	int	No	10000	Rows per chunk
delimiter	str	No	auto-detect	Column delimiter

* At least one of input_file or df must be provided.

Algorithm

For each value:

1. Normalize: strip() + lower()
2. For each secret salt: SHA-512(value + salt) → 128-char hex string
3. Use the output of one round as input to the next

Null/NaN values are returned as None without hashing.

CLI Reference

d2-hasher --input-file FILE --columns COL [COL ...] --secret-salts SALT [SALT ...]
          [--output FILE] [--chunksize N] [--delimiter CHAR]

License

MIT