Galois Message Authentication Code (GMAC) is an authentication-only variant of the GCM which can form an incremental message authentication code. Both GCM and GMAC can accept initialization vectors of arbitrary length.

Jun 15, 2016 · This document, The Galois/Counter Mode (GCM) and GMAC Validation System (GCMVS), specifies the procedures for validating implementations of the Galois/Counter Mode (GCM), an algorithm for authenticated encryption with associated data, and its specialization, GMAC, for generating a message authentication code (MAC) on data that is not

This document specifies the conventions for using the AES-GMAC Message Authentication Code algorithm with the Cryptographic Message Syntax (CMS) as specified in RFC 5652.

An implementation of AES-GCM can be used to compute the GMAC message authentication code by providing the content-authentication key as the AES key, the nonce as the initialization vector, a zero-length plaintext content, and the content to be authenticated as the additional authenticated data (AAD).

Jun 3, 2020 · 对应到上图中的消息认证码，GMAC就是利用伽罗华域 (Galois Field，GF，有限域)乘法运算来计算消息的MAC值。假设秘钥长度为128bits, 当密文大于128bits时，需要将密文按128bits进行分组。 应用流程如下图： GCM中的G就是指GMAC，C就是指CTR。 GCM可以提供对消息的加密和完整性校验，另外，它还可以提供附加消息的完整性校验。 在实际应用场景中，有些信息是我们不需要保密，但信息的接收者需要确认它的真实性的，例如源IP，源端口，目 …

Nov 28, 2007 · This Recommendation specifies the Galois/Counter Mode (GCM), an algorithm for authenticated encryption with associated data, and its specialization, GMAC, for generating a message authentication code (MAC) on data that is not encrypted. GCM and GMAC are modes of operation for an underlying approved... See full abstract

Abstract This memo describes the use of the Advanced Encryption Standard (AES) Galois Message Authentication Code (GMAC) as a mechanism to provide data origin authentication, but not confidentiality, within the IPsec Encapsulating …

GCM is constructed from an approved symmetric key block cipher with a block size of 128 bits, such as the Advanced Encryption Standard (AES) algorithm that is specified in Federal Information Processing Standard (FIPS) Pub. 197 [2]. Thus, GCM is …

Mar 10, 2009 · This document reviews the use of the Galois/Counter Mode (GCM) and Galois Message Authentication Code (GMAC) modes of operation for the Advanced Encryption Standard as they are used in the Encapsulating Security Payload (ESP) (Kent, S., “IP Encapsulating Security Payload (ESP),” December 2005.).

Jan 7, 2021 · AES-GCM is symmetric encryption (the same key is used to encrypt and decrypt). So, I'm struggling with the idea of using symmetric encryption for signing.