hash_names {epitrix}

Anonymise data using scrypt

Description

This function uses the scrypt algorithm from libsodium to anonymise data, based on user-indicated data fields. Data fields are concatenated first, then each entry is hashed. The function can either return a full detailed output, or short labels ready to use for 'anonymised data'. Before concatenation (using "_" as a separator) to form labels, inputs are modified using [clean_labels()]

Usage

hash_names(
  ...,
  size = 6,
  full = TRUE,
  hashfun = "secure",
  salt = NULL,
  clean_labels = TRUE
)

Arguments

...

Data fields to be hashed.

size

The number of characters retained in the hash.

full

A logical indicating if the a full output should be returned as a data.frame, including original labels, shortened hash, and full hash.

hashfun

This defines the hashing function to be used. If you specify "secure" (default), it will use [sodium::scrypt()], which will be secure, but will be slow for large data sets. For fast hashing with no colisions, you can sepecify "fast", and it will use [sodium::sha256()], which is several orders of magnitude faster than [sodium::scrypt()]. You can also specify a hashing function that takes and returns a [raw][base::raw] vector of bytes that can be converted to character with [rawToChar()].

salt

An optional object that can be coerced to a character to be used to 'salt' the hashing algorithm (see details). Ignored if 'NULL'.

clean_labels

A logical indicating if labels of variables should be standardized; defaults to 'TRUE'

Details

The argument 'salt' should be used for salting the algorithm, i.e. adding an extra input to the input fields (the 'salt') to change the resulting hash and prevent identification of individuals via pre-computed hash tables.

It is highly recommend to choose a secret, random salt in order make it harder for an attacker to decode the hash.

Author(s)

Thibaut Jombart [e-mail], Dirk Shchumacher [e-mail], Zhian N. Kamvar [e-mail]

See Also

[clean_labels()], used to clean labels prior to hashing
[sodium::hash()] for available hashing functions.

Examples

first_name <- c("Jane", "Joe", "Raoul")
last_name <- c("Doe", "Smith", "Dupont")
age <- c(25, 69, 36)

# secure hashing
hash_names(first_name, last_name, age, hashfun = "secure")

# fast hashing
hash_names(first_name, last_name, age,
           size = 8, full = FALSE, hashfun = "fast")


## salting the hashing (more secure!)

hash_names(first_name, last_name) # unsalted - less secure
hash_names(first_name, last_name, salt = 123) # salted with an integer
hash_names(first_name, last_name, salt = "foobar") # salted with an character

## using a different hash algorithm if you want things to run faster

hash_names(first_name, last_name, hashfun = "fast") # use sha256 algorithm