---
name: "cryptopANT"
section: "3"
platform: "linux"
package: "libcryptopant-dev"
version: "1.3.1-3"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/cryptopANT"
---

# cryptopANT(3)

IP Address Anonymization Library

## NAME

cryptopANT - IP Address Anonymization Library

## SYNOPSIS

```
#include <cryptopANT.h>
```

## DESCRIPTION

**The cryptopANT ip address anonymization library** **implements techniques for IPv4 and IPv6 address anonymization first** **described in:**

- 'Prefix-Preserving IP Address Anonymization',

    *Computer Networks, Volume 46, Issue 2, 7 October 2004, Pages 253-272, Elsevier.*

**commonly known as Crypto-PAn.**

**This implementation is provided by USC/ISI ANT project:** **http://ant.isi.edu**

### **int scramble\_init\_from\_file(const char \*keyfile, scramble\_crypt\_t c4, scramble\_crypt\_t c6, int \*do\_mac)**

### API Overview

-

  **Initializes library from a keyfile and sets up underlying cryptographical mechanism for scrambling** **of IPv4 (c4) and IPv6 (c6) addresses.  See**  **scramble\_crypt\_t** **for possible values of c4 and c6.  Typically used are:** **SCRAMBLE\_NONE** **for no scrambling or** **SCRAMBLE\_AES** **for scrambling using fast AES cypher.  If the keyfile does not exist, it is created.** **This function internally calls** **scramble\_readstate()** **and** **scrable\_init().** **Returns 0 if successful.** **SCRAMBLE\_BLOWFISH** **uses blowfish cypher.  While previously widely used, it's no longer recommended, as scrambling** **of ipv6 addresses can be very slow.**

```
int32_t   scramble_ip4(uint32_t input, int pass_bits)
int32_t unscramble_ip4(uint32_t input, int pass_bits)
```

-

  **Scrambles or un-scrambles (input) IP address passing through first (pass\_bits); the scrambled** **ip address is returned.  Please note that even if (pass\_bits) is 0, first few** **bits will be passed through to preserve class of the input IP.  Both input and** **output IPs are in network byte order.** **Note that unscrambling is a costly operation and unscrambling a large number** **of different addresses can take a long time.**

```
void   scramble_ip6(struct in6_addr *input, int pass_bits)
void unscramble_ip6(struct in6_addr *input, int pass_bits)
```

-

  **Scrambles or un-scrambles IPv6 address pointed to by (input)**  **in-place** **, passing through first (pass\_bits).  Addresses are in network byte order.** **Note that unscrambling is a costly operation and unscrambling a large number** **of different addresses can take a long time.**

```
int scramble_readstate(const char *keyfile, scramble_state_t *s)
int scramble_savestate(const char *keyfile, const scramble_state_t *s)
```

-

  **These functions can read scrambling keys from keyfile into** **memory pointed to by (s), or save/write previously initialized state (s)** **to a (keyfile).  After state is read, the library still needs to be**  **initialized by calling** **scramble\_init()** **Return 0 on success.**

```
int scramble_init(const scramble_state_t *s)
```

-

  **Initializes library using state pointed by (s).  Returns 0 on success.**

## SEE ALSO

**scramble\_ips**

-

  **is a binary for anonymizing textual IP addresses, which comes packaged with this library**

## AUTHORS

**The cryptopANT library was written by**

- Yuri Pradkin,

  **University of Southern California, Information Sciences Institute, CA.**

**The current version is available from "ANT Project"'s Web site at**

*http://ant.isi.edu*

## BUGS

**Please send problems, bugs, questions, desirable enhancements, etc. to:**

**ant@isi.edu**