The `diffpriv`

package makes privacy-aware data science in
R easy. `diffpriv`

implements the formal framework of
differential privacy: differentially-private mechanisms can safely
release to untrusted third parties: statistics computed, models fit, or
arbitrary structures derived on privacy-sensitive data. Due to the
worst-case nature of the framework, mechanism development typically
requires involved theoretical analysis. `diffpriv`

offers a
turn-key approach to differential privacy by automating this process
with sensitivity sampling in place of theoretical sensitivity
analysis.

Obtaining `diffpriv`

is easy. From within R:

```
## Install the development version of diffpriv from GitHub:
install.packages("devtools")
::install_github("brubinstein/diffpriv") devtools
```

A typical example in differential privacy is privately releasing a
simple `target`

function of privacy-sensitive input data
`X`

. Say the mean of `numeric`

data:

```
## a target function we'd like to run on private data X, releasing the result
<- function(X) mean(X) target
```

First load the `diffpriv`

package (installed as above) and
construct a chosen differentially-private mechanism for privatizing
`target`

.

```
## target seeks to release a numeric, so we'll use the Laplace mechanism---a
## standard generic mechanism for privatizing numeric responses
library(diffpriv)
<- DPMechLaplace(target = target) mech
```

To run `mech`

on a dataset `X`

we must first
determine the sensitivity of `target`

to small changes to
input dataset. One avenue is to analytically bound sensitivity (on
paper; see the vignette)
and supply it via the `sensitivity`

argument of mechanism
construction: in this case not hard if we assume bounded data, but in
general sensitivity can be very non-trivial to calculate manually. The
other approach, which we follow in this example, is sensitivity
sampling: repeated probing of `target`

to estimate
sensitivity automatically. We need only specify a distribution for
generating random probe datasets; `sensitivitySampler()`

takes care of the rest. The price we pay for this convenience is the
weaker form of random differential privacy.

```
## set a dataset sampling distribution, then estimate target sensitivity with
## sufficient samples for subsequent mechanism responses to achieve random
## differential privacy with confidence 1-gamma
<- function(n) rnorm(n)
distr <- sensitivitySampler(mech, oracle = distr, n = 5, gamma = 0.1)
mech #> Sampling sensitivity with m=285 gamma=0.1 k=285
@sensitivity ## DPMech and subclasses are S4: slots accessed via @
mech#> [1] 0.8089517
```

With a sensitivity-calibrated mechanism in hand, we can release
private responses on a dataset `X`

, displayed alongside the
non-private response for comparison:

```
<- c(0.328,-1.444,-0.511,0.154,-2.062) # length is sensitivitySampler() n
X <- releaseResponse(mech, privacyParams = DPParamsEps(epsilon = 1), X = X)
r cat("Private response r$response: ", r$response,
"\nNon-private response target(X):", target(X))
#> Private response r$response: -1.119506
#> Non-private response target(X): -0.707
```

The above example demonstrates the main components of
`diffpriv`

:

- Virtual class
`DPMech`

for generic mechanisms that captures the non-private`target`

and releases privatized responses from it. Current subclasses`DPMechLaplace`

,`DPMechGaussian`

: the Laplace and Gaussian mechanisms for releasing numeric responses with additive noise;`DPMechExponential`

: the exponential mechanism for privately optimizing over finite sets (which need not be numeric); and`DPMechBernstein`

: the Bernstein mechanism for privately releasing multivariate real-valued functions. See the bernstein vignette for more.

- Class
`DPParamsEps`

and subclasses for encapsulating privacy parameters. `sensitivitySampler()`

method of`DPMech`

subclasses estimates target sensitivity necessary to run`releaseResponse()`

of`DPMech`

generic mechanisms. This provides an easy alternative to exact sensitivity bounds requiring mathematical analysis. The sampler repeatedly probes`DPMech@target`

to estimate sensitivity to data perturbation. Running mechanisms with obtained sensitivities yield random differential privacy.

Read the package vignette for more, or news for the latest release notes.

`diffpriv`

is an open-source package offered with a
permissive MIT License. Please acknowledge use of `diffpriv`

by citing the paper on the sensitivity sampler:

Benjamin I. P. Rubinstein and Francesco Aldà. “Pain-Free Random Differential Privacy with Sensitivity Sampling”, to appear in the 34th International Conference on Machine Learning (ICML’2017), 2017.

Other relevant references to cite depending on usage:

**Differential privacy and the Laplace mechanism:**Cynthia Dwork, Frank McSherry, Kobbi Nissim, and Adam Smith. “Calibrating noise to sensitivity in private data analysis.” In Theory of Cryptography Conference, pp. 265-284. Springer Berlin Heidelberg, 2006.**The Gaussian mechanism:**Cynthia Dwork and Aaron Roth. “The algorithmic foundations of differential privacy.” Foundations and Trends in Theoretical Computer Science 9(3–4), pp. 211-407, 2014.**The exponential mechanism:**Frank McSherry and Kunal Talwar. “Mechanism design via differential privacy.” In the 48th Annual IEEE Symposium on Foundations of Computer Science (FOCS’07), pp. 94-103. IEEE, 2007.**The Bernstein mechanism:**Francesco Aldà and Benjamin I. P. Rubinstein. “The Bernstein Mechanism: Function Release under Differential Privacy.” In Proceedings of the 31st AAAI Conference on Artificial Intelligence (AAAI’2017), pp. 1705-1711, 2017.**Random differential privacy:**Rob Hall, Alessandro Rinaldo, and Larry Wasserman. “Random Differential Privacy.” Journal of Privacy and Confidentiality, 4(2), pp. 43-59, 2012.