Hacker News: HashML-DSA Considered Harmful

Source URL: https://keymaterial.net/2024/11/05/hashml-dsa-considered-harmful/
Source: Hacker News
Title: HashML-DSA Considered Harmful

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AI Summary and Description: Yes

Summary: The text discusses the complexities surrounding prehashing in digital signature schemes, particularly in the context of recent NIST standards. It offers insights on how to effectively manage private key exposure while facilitating remote signing processes, highlighting the shortcomings of current proposals like HashML-DSA and HashSLH-DSA.

Detailed Description:
The document addresses a critical area in cryptography focusing on signature schemes and prehashing challenges. It emphasizes the underlying technical issues with existing paradigms and suggests improvements to ensure security and efficiency in digital signatures, especially when used with hardware security modules (HSMs) and cloud services.

Key Points:
– **Signature Scheme Overview**: Introduces the basic functions involved in signature schemes (Key Generation, Signing, and Verification) and notes the significance of ensuring that a signature produced will successfully verify.

– **Challenges with Large Data**: Discusses the difficulty of using large messages in signing processes, particularly when private keys are located in remote systems, such as HSMs or cloud platforms. Highlights the implications of managing state during the signing process.

– **Proposed Solutions**:
– Introduces a stream-based signing approach that allows for large pieces of data to be processed in chunks without the need for large data transfers.
– Suggests a design pattern that includes initializing, updating, and finalizing the signing process to enhance efficiency while retaining security around the private key.

– **NIST Standardization Insights**:
– Mentions NIST’s standardization of new signature algorithms (ML-DSA, SLH-DSA, HashML-DSA, and HashSLH-DSA), critiquing how they handle the complexities of signature processing, particularly the non-resignability property encouraged by NIST.
– Critiques the HashML-DSA and HashSLH-DSA as inadequate for addressing prehashing issues, expressing concerns over their reliance on additional parameters and the implication that they introduce unnecessary complexity and potential security vulnerabilities.

– **Importance of Protocols**:
– Stresses the role of protocols in signature schemes, emphasizing that they should dictate what data gets signed and how, as well as their security implications. Proposes signing the hash of data rather than the raw data itself to improve compatibility with systems managing large datasets.

– **Conclusion**:
– Ultimately, reinforces the idea that the introduction of poorly-conceived signature schemes can complicate security frameworks and advocates for adhering to well-defined, traditional schemes to avoid misalignments in cryptographic procedures.

For professionals in AI, cloud, and infrastructure security, the text underscores critical considerations when implementing digital signature schemes, particularly regarding data integrity and the management of sensitive cryptographic materials in distributed environments.