CCM Encryption with 64-bit Block Ciphers for IoT

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Solution Overview

Problem

Current computing devices rely on 128-bit block ciphers like AES for CCM encryption, which is not suitable for resource-constrained devices such as IoT devices, as it requires larger footprints and less flexible message size adjustments.

Innovation Solution

Implementing CCM encryption using 64-bit block ciphers, allowing for smaller footprint and more granular message size adjustments by performing CBC-MAC authentication and counter mode encryption operations with a 64-bit block cipher algorithm, suitable for devices like IoT devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If 128-bit block ciphers like AES are used for CCM encryption, then security and confidentiality are improved, but device footprint and resource requirements increase

Engineering Contradiction:

ImprovesecurityVSAvoiddevice footprint

Core Design Contradiction:

ReliabilityVSWeight of stationary object

Solution Approach 1:

The patent changes the block cipher parameter from 128-bit to 64-bit, adapting the CCM encryption mode to work with smaller block sizes. This allows resource-constrained devices to implement authenticated encryption with reduced footprint while maintaining security through proper adaptation of the encryption and authentication processes.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent makes the CCM encryption mode universal by enabling it to work with both traditional 128-bit block ciphers and 64-bit block ciphers. This multi-functionality allows the same encryption framework to serve both high-security applications and resource-constrained IoT devices.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If 128-bit block ciphers are used for CCM encryption, then encryption strength is improved, but flexibility in message size adjustments deteriorates

Engineering Contradiction:

Improveencryption strengthVSAvoidflexibility in message size adjustments

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent changes the block size parameter from 128-bit to 64-bit, which fundamentally alters how message data is processed and padded. This enables more granular control over message size handling, allowing for better adaptability to varying message lengths while maintaining encryption strength through the authenticated encryption mechanism.

Inventive Principle:

Principle #35Parameter changes

3Weight of stationary object

If 64-bit block ciphers are used for CCM encryption, then device footprint is reduced, but security requirements may be compromised

Engineering Contradiction:

Improvedevice footprintVSAvoidsecurity

Core Design Contradiction:

Weight of stationary objectVSReliability

Solution Approach 1:

The patent segments the security function into two independent but complementary operations: a 64-bit block cipher for encryption and a separate CBC-MAC authentication code for verifying data integrity and authenticity. This segmentation allows the use of lighter cryptographic primitives while maintaining overall security through the combined authenticated encryption mechanism.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent creates a composite cryptographic system by combining 64-bit block cipher encryption with CBC-MAC authentication. This composite approach uses multiple cryptographic layers to achieve security comparable to traditional systems while reducing the resource requirements of individual components.

Inventive Principle:

Principle #40Composite materials

4Use of energy by moving object

If 64-bit block ciphers are used for CCM encryption, then resource consumption is reduced, but compatibility with existing 128-bit standards deteriorates

Engineering Contradiction:

Improveresource consumptionVSAvoidcompatibility with existing standards

Core Design Contradiction:

Use of energy by moving objectVSAdaptability or versatility

Solution Approach 1:

The patent designs a universal CCM encryption framework that can operate with both 128-bit and 64-bit block ciphers. This multi-functionality ensures compatibility with existing 128-bit standards while enabling deployment on resource-constrained devices that require 64-bit ciphers, allowing seamless adaptation across different platforms and protocols.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS10404468B2Technologies for CCM encryption with 64-bit block ciphers

Publication Date: 2019.09.03 INTEL CORP

AI summary

Technologies for counter with CBC-MAC (CCM) mode encryption include a computing device that performs a CBC-MAC authentication operation on a message with an encryption key, using a 64-bit block cipher to generate a message authentication code. The computing device generates a first 64-bit authentication block including an 8-bit flag field and a length field of between 11 and 32 bits. The flag field indicates the length of the length field. Performing the CBC-MAC authentication operation includes formatting the message into one or more 64-bit authentication blocks. The computing device performs a counter mode encryption operation on the message with the encryption key using the 64-bit block cipher to generate a cipher text. Performing the counter mode encryption includes generating multiple 64-bit keystream blocks. The computing device generates an authentication tag based on the message authentication code and a first keystream block of keystream blocks. Other embodiments are described and claimed.