Attacks against industrial control systems (ICSs) often exploit the insufficiency of authentication mechanisms. Verifying whether the received messages are intact and issued by legitimate sources can prevent malicious data/command injection by illegitimate or compromised devices. However, the key challenge is to introduce message authentication for various ICS communication models, including multicast or broadcast, with a messaging rate that can be as high as thousands of messages per second, within very stringent latency constraints. For example, certain commands for protection in smart grids must be delivered within 2 milliseconds, ruling out public-key cryptography. This paper proposes two lightweight message authentication schemes, named CMA and its multicast variant CMMA, that perform precomputation and caching to authenticate future messages. With minimal precomputation and communication overhead, C(M)MA eliminates all cryptographic operations for the source after the message is given, and all expensive cryptographic operations for the destinations after the message is received. C(M)MA considers the urgency profile (or likelihood) of a set of future messages for even faster verification of the most time-critical (or likely) messages. We demonstrate the feasibility of C(M)MA in an ICS setting based on a substation automation system in smart grids.

翻译：针对工业控制系统的攻击通常利用了认证机制的不足。验证接收消息是否完整且由合法来源发出，可防止非法或受损设备注入恶意数据/命令。然而，关键挑战在于为包括多播或广播在内的各种工业控制系统通信模型引入消息认证，同时满足每秒数千条消息的高传输速率以及极为严格的延迟约束。例如，智能电网中的某些保护命令必须在2毫秒内传输，这使得公钥密码学不可行。本文提出两种轻量级消息认证方案，即CMA及其多播变体CMMA，通过预计算与缓存技术对后续消息进行认证。在极少的预计算与通信开销下，C(M)MA消除了消息生成后发送方的所有密码学操作，以及接收方收到消息后的所有高成本密码学操作。C(M)MA通过考虑未来消息的紧急度（或可能性），实现对最紧急（或可能性最高）消息的更快速验证。我们基于智能电网中的变电站自动化系统，在工业控制系统场景中验证了C(M)MA的可行性。