Security and Privacy Considerations for IPv6 Address Generation Mechanisms

Abstract

This document discusses privacy and security considerations for several IPv6 address generation mechanisms, both standardized and non-standardized. It evaluates how different mechanisms mitigate different threats and the trade-offs that implementors, developers, and users face in choosing different addresses or address generation mechanisms.

Recommendation on Stable IPv6 Interface Identifiers

“…Stable address: An address that does not vary over time within the same network (as defined in [RFC7721]). …”

“…The security and privacy implications of embedding a stable linklayer address in an IPv6 IID have been known for some time now and are discussed in great detail in [RFC7721]. They include: More generally, the reuse of identifiers that have their own semantics or properties across different contexts or scopes can be detrimental for security and privacy [NUM-IDS].…”

Privacy Considerations for IPv6 Adaptation-Layer Mechanisms

“…In terms of privacy threats discussed in [RFC7721], the one with the need for the most entropy is address scans of routable addresses. To mitigate address scans, one needs enough entropy to make the probability of a successful address probe be negligible.…”

“…Introduction RFC 6973 [RFC6973] discusses privacy considerations for Internet protocols, and Section 5.2 of that document covers a number of privacy-specific threats. In the context of IPv6 addresses, Section 3 of [RFC7721] provides further elaboration on the applicability of the privacy threats.…”

Privacy Considerations for DHCPv6

“…That knowledge can be used for device-specific vulnerability exploitation attacks. See Section 3.4 of [RFC7721] for a discussion about this type of attack.…”