The article argues that while "Diffie-Hellman" is often used as a generic term for key exchange, the original finite field Diffie-Hellman (FFDH) is effectively obsolete in practice. Due to its vulnerability to sub-exponential attacks, FFDH requires impractically large key sizes for adequate security. Elliptic Curve Diffie-Hellman (ECDH), leveraging the discrete logarithm problem on elliptic curves, offers significantly stronger security with smaller key sizes, making it the dominant and practically relevant implementation of the Diffie-Hellman key exchange concept. Thus, when discussing real-world applications, "Diffie-Hellman" almost invariably implies ECDH, rendering FFDH a largely theoretical or historical curiosity.
The author used Sentence-BERT (SBERT), a semantic similarity model, to analyze the Voynich Manuscript, hoping to uncover hidden structure. They treated each line of "Voynichese" as a separate sentence and embedded them using SBERT, then visualized these embeddings in a 2D space using UMAP. While visually intriguing patterns emerged, suggesting some level of semantic organization within sections of the manuscript, the author acknowledges that this doesn't necessarily mean the text is meaningful or decipherable. They released their code and data, inviting further exploration and analysis by the community. Ultimately, the project demonstrated a novel application of SBERT to a historical mystery but stopped short of cracking the code itself.
HN commenters are generally skeptical of the analysis presented. Several point out the small sample size and the risk of overfitting when dealing with such limited data. One commenter notes that previous NLP analysis using Markov chains produced similar results, suggesting the observed "structure" might be an artifact of the method rather than a genuine feature of the manuscript. Another expresses concern that the approach doesn't account for potential cipher keys or transformations, making the comparison to known languages potentially meaningless. There's a general feeling that while interesting, the analysis doesn't provide strong evidence for or against any particular theory about the Voynich Manuscript's origins. A few commenters request more details about the methodology and specific findings to better assess the claims.
John L. Young, co-founder of Cryptome, a crucial online archive of government and corporate secrets, passed away. He and co-founder Deborah Natsios established Cryptome in 1996, dedicating it to publishing information suppressed for national security or other questionable reasons. Young tirelessly defended the public's right to know, facing numerous legal threats and challenges for hosting controversial documents, including internal memos, manuals, and blueprints. His unwavering commitment to transparency and freedom of information made Cryptome a vital resource for journalists, researchers, and activists, leaving an enduring legacy of challenging censorship and promoting open access to information.
HN commenters mourn the loss of John Young, co-founder of Cryptome, highlighting his dedication to free speech and government transparency. Several share anecdotes showcasing Young's uncompromising character and the impact Cryptome had on their lives. Some discuss the site's role in publishing sensitive documents and the subsequent government pressure, admiring Young's courage in the face of legal threats. Others praise the simple, ad-free design of Cryptome as a testament to its core mission. The overall sentiment expresses deep respect for Young's contribution to online freedom of information.
Passkeys leverage public-key cryptography to enhance login security. Instead of passwords, they utilize a private key stored on the user's device and a corresponding public key registered with the online service. During login, the device uses its private key to sign a challenge issued by the service, proving possession of the correct key without ever transmitting it. This process, based on established cryptographic principles and protocols like WebAuthn, eliminates the vulnerability of transmitting passwords and mitigates phishing attacks, as the private key never leaves the user's device and is tied to a specific website. This model ensures only the legitimate device can authenticate with the service.
Hacker News users discussed the practicality and security implications of passkeys. Some expressed concern about vendor lock-in and the reliance on single providers like Apple, Google, and Microsoft. Others questioned the robustness of the recovery mechanisms and the potential for abuse or vulnerabilities in the biometric authentication process. The convenience and improved security compared to passwords were generally acknowledged, but skepticism remained about the long-term viability and potential for unforeseen issues with widespread adoption. A few commenters delved into the technical details, discussing the cryptographic primitives used and the specific aspects of the FIDO2 standard, while others focused on the user experience and potential challenges for less tech-savvy users.
The Linux kernel utilizes a PGP web of trust for verifying code contributions, aiming to ensure authenticity and integrity. Maintainers hold signing keys and form a decentralized trust network. Contributions are signed by developers and validated against this network through a chain of trust leading back to a trusted maintainer. While the system isn't foolproof and relies heavily on the integrity of maintainers, it significantly raises the bar for malicious code injection by requiring cryptographic signatures for patches. This web of trust, although complex, helps secure the kernel's development process and bolster confidence in its overall security.
HN commenters discuss the complexities and practical limitations of the Linux kernel's PGP web of trust. Some highlight the difficulty in verifying identities and the trust placed in maintainers, expressing skepticism about its effectiveness against sophisticated attackers. Others point out the social element, with trust built on personal connections and reputation within the community. A few suggest alternative approaches like a "root of trust" maintained by Linus Torvalds or a more centralized system, acknowledging the trade-offs between security and practicality. Several comments also delve into the technical details of key signing parties and the challenges of managing a large and distributed web of trust. The overall sentiment seems to be one of cautious respect for the system, acknowledging its imperfections while appreciating its role in maintaining the integrity of the Linux kernel.
Sneakers (1992) follows Martin Bishop, a security expert with a checkered past, who leads a team of specialists testing corporate security systems. They are blackmailed into stealing a powerful decryption device, forcing them to navigate a dangerous world of espionage and corporate intrigue. As they uncover a conspiracy involving the NSA and potentially global surveillance, Bishop and his team must use their unique skills to retrieve the device and expose the truth before it falls into the wrong hands. The 4K Blu-ray release boasts improved picture and sound quality, bringing the classic thriller to life with enhanced detail.
Hacker News users discuss the film Sneakers (1992), praising its realistic portrayal of hacking and social engineering, especially compared to modern depictions. Several commenters highlight the film's prescient themes of privacy and surveillance, noting how relevant they remain today. The cast, particularly Redford, Poitier, and Hackman, receives considerable praise. Some lament the lack of similar "caper" films made recently, with a few suggestions for comparable movies offered. A discussion unfolds around the technical accuracy of the "Setec Astronomy" MacGuffin, with varying perspectives on its plausibility. The overall sentiment is one of strong nostalgia and appreciation for Sneakers as a well-crafted and thought-provoking thriller.
This Stanford article explores the vulnerabilities of car key fobs to relay attacks. These attacks exploit the limited range of key fob signals by using two relay devices: one near the car and one near the key fob. The relay devices capture and transmit the signals between the key fob and the car, effectively extending the key's range and allowing thieves to unlock and even start the car without physical possession of the key. The article details various attack scenarios, including rolling code exploitation and amplification attacks, and discusses potential countermeasures such as signal jamming, distance bounding, and cryptographic authentication improvements to enhance car security.
The Hacker News comments discuss practical experiences and technical details related to car key fob vulnerabilities. Several users share anecdotes of relay attacks, highlighting their increasing prevalence and ease of execution with readily available hardware. Some commenters debate the effectiveness of various mitigation strategies like Faraday cages and rolling codes, acknowledging the limitations of each. Others delve into the technical aspects of the attacks, discussing signal amplification, frequency hopping, and the possibility of jamming vulnerabilities. The overall sentiment expresses concern over the security of these systems and the relative ease with which they can be compromised, with some advocating for greater industry attention to these vulnerabilities.
Jonathan Protzenko announced the release of Evercrypt 1.0 for Python, providing a high-assurance cryptography library with over 15,000 lines of formally verified code. This release leverages the HACL* cryptographic library, which has been mathematically proven correct, and makes it readily available for Python developers through a simple and performant interface. Evercrypt aims to bring robust, verified cryptographic primitives to a wider audience, improving security and trustworthiness for applications that depend on strong cryptography. It offers a drop-in replacement for existing libraries, significantly enhancing the security guarantees without requiring extensive code changes.
Hacker News users discussed the implications of having 15,000 lines of verified cryptography in Python, focusing on the trade-offs between verification and performance. Some expressed skepticism about the practical benefits of formal verification for cryptographic libraries, citing the difficulty of verifying real-world usage and the potential performance overhead. Others emphasized the importance of correctness in cryptography, arguing that verification offers valuable guarantees despite its limitations. The performance costs were debated, with some suggesting that the overhead might be acceptable or even negligible in certain scenarios. Several commenters also discussed the challenges of formal verification in general, including the expertise required and the limitations of existing tools. The choice of Python was also questioned, with some suggesting that a language like OCaml might be more suitable for this type of project.
Trail of Bits is developing a new Python API for working with ASN.1 data, aiming to address shortcomings of existing libraries. This new API prioritizes safety, speed, and ease of use, leveraging modern Python features like type hints and asynchronous operations. It aims to simplify encoding, decoding, and manipulation of ASN.1 structures, while offering improved error handling and comprehensive documentation. The project is currently in an early stage, with a focus on supporting common ASN.1 types and encoding rules like BER, DER, and CER. They're soliciting community feedback to help shape the API's future development and prioritize features.
Hacker News users generally expressed enthusiasm for the new ASN.1 Python API showcased by Trail of Bits. Several commenters highlighted the pain points of existing ASN.1 tools, praising the new library's focus on safety and ease of use. Specific positive mentions included the type-safe design, Pythonic API, and clear documentation. Some users shared their struggles with ASN.1 decoding in the past and expressed interest in trying the new library. The overall sentiment was one of welcoming a modern and improved approach to working with ASN.1 in Python.
Starting September 13, 2024, the maximum lifetime for publicly trusted TLS certificates will be reduced to 398 days (effectively 47 days due to calculation specifics). This change, driven by the CA/Browser Forum, aims to improve security by limiting the impact of compromised certificates and encouraging more frequent certificate renewals, promoting better certificate hygiene and faster adoption of security improvements. While automation is key to managing this shorter lifespan, the industry shift will require organizations to adapt their certificate lifecycle processes.
Hacker News users generally express frustration and skepticism towards the reduced TLS certificate lifespan. Many commenters believe this change primarily benefits certificate authorities (CAs) financially, forcing more frequent purchases. Some argue the security benefits are minimal and outweighed by the increased operational burden on system administrators, particularly those managing numerous servers or complex infrastructures. Several users suggest automation is crucial to cope with shorter lifespans and highlight existing tools like certbot. Concerns are also raised about the potential for increased outages due to expired certificates and the impact on smaller organizations or individual users. A few commenters point out potential benefits like faster revocation of compromised certificates and quicker adoption of new cryptographic standards, but these are largely overshadowed by the negative sentiment surrounding the increased administrative overhead.
The blog post "AES and ChaCha" compares two popular symmetric encryption algorithms, highlighting ChaCha's simplicity and speed advantages, particularly in software implementations and resource-constrained environments. While AES, the Advanced Encryption Standard, is widely adopted and hardware-accelerated, its complex structure makes it more challenging to implement securely in software. ChaCha, designed with software in mind, offers easier implementation, potentially leading to fewer vulnerabilities. The post concludes that while both algorithms are considered secure, ChaCha's streamlined design and performance benefits make it a compelling alternative to AES, especially in situations where hardware acceleration isn't available or software implementation is paramount.
HN commenters generally praised the article for its clear and concise explanation of ChaCha and AES, particularly appreciating the accessible language and lack of jargon. Some discussed the practical implications of choosing one cipher over the other, highlighting ChaCha's performance advantages on devices lacking AES hardware acceleration and its resistance to timing attacks. Others pointed out that while simplicity is desirable, security and correctness are paramount in cryptography, emphasizing the rigorous scrutiny both ciphers have undergone. A few commenters delved into more technical aspects, such as the internal workings of the algorithms and the role of different cipher modes. One commenter offered a cautionary note, reminding readers that even well-regarded ciphers can be vulnerable if implemented incorrectly.
This blog post explains how one-time passwords (OTPs), specifically HOTP and TOTP, work. It breaks down the process of generating these codes, starting with a shared secret key and a counter (HOTP) or timestamp (TOTP). This input is then used with the HMAC-SHA1 algorithm to create a hash. The post details how a specific portion of the hash is extracted and truncated to produce the final 6-digit OTP. It clarifies the difference between HOTP, which uses a counter and requires manual synchronization if skipped, and TOTP, which uses time and allows for a small window of desynchronization. The post also briefly discusses the security benefits of OTPs and why they are effective against certain types of attacks.
HN users generally praised the article for its clear explanation of HOTP and TOTP, breaking down complex concepts into understandable parts. Several appreciated the focus on building the algorithms from the ground up, rather than just using libraries. Some pointed out potential security risks, such as replay attacks and the importance of secure time synchronization. One commenter suggested exploring WebAuthn as a more secure alternative, while another offered a link to a Python implementation of the algorithms. A few discussed the practicality of different hashing algorithms and the history of OTP generation methods. Several users also appreciated the interactive code examples and the overall clean presentation of the article.
Betty Webb, a code breaker at Bletchley Park during World War II, has died at age 101. She worked in Hut 6, decrypting German Enigma messages, a vital contribution to the Allied war effort. After the war, she joined GCHQ, Britain's signals intelligence agency, before eventually leaving to raise a family. Her work at Bletchley Park remained secret for decades, highlighting the dedication and secrecy surrounding those involved in breaking the Enigma code.
HN commenters offer condolences and share further details about Betty Webb's life and wartime contributions at Bletchley Park. Several highlight her humility, noting she rarely spoke of her work, even to family. Some commenters discuss the vital yet secretive nature of Bletchley Park's operations, and the remarkable contributions of the women who worked there, many of whom are only now being recognized. Others delve into the specific technologies used at Bletchley, including the Colossus Mark 2 computer, with which Webb worked. A few commenters also share links to obituaries and other relevant information.
Lehmer's continued fraction factorization algorithm offers a way to find factors of a composite integer n. It leverages the convergents of the continued fraction expansion of √n to generate pairs of integers x and y such that x² ≡ y² (mod n). If x is not congruent to ±y (mod n), then gcd(x-y, n) and gcd(x+y, n) will yield non-trivial factors of n. While not as efficient as more advanced methods like the general number field sieve, it provides a relatively simple approach to factorization and serves as a stepping stone towards understanding more complex techniques.
Hacker News users discuss Lehmer's algorithm, mostly focusing on its impracticality despite its mathematical elegance. Several commenters point out the exponential complexity, making it slower than trial division for realistically sized numbers. The discussion touches upon the algorithm's reliance on finding small quadratic residues, a process that becomes computationally expensive quickly. Some express interest in its historical significance and connection to other factoring methods, while others question the article's claim of it being "simple" given its actual complexity. A few users note the lack of practical applications, emphasizing its theoretical nature. The overall sentiment leans towards appreciation of the mathematical beauty of the algorithm but acknowledges its limited real-world use.
Fly.io's blog post details their experience implementing and using macaroons for authorization in their distributed system. They highlight macaroons' advantages, such as decentralized authorization and context-based access control, allowing fine-grained permissions without constant server-side checks. The post outlines the challenges they faced operationalizing macaroons, including managing key rotation, handling third-party caveats, and ensuring efficient verification, and explains their solutions using a centralized root key service and careful caveat design. Ultimately, Fly.io found macaroons effective for their use case, offering flexibility and performance improvements.
HN commenters generally praised the article for its clarity in explaining the complexities of macaroons. Some expressed their prior struggles understanding the concept and appreciated the author's approach. A few commenters discussed potential use cases beyond authorization, such as for building auditable systems and enforcing data governance policies. The extensibility and composability of macaroons were highlighted as key advantages. One commenter noted the comparison to JSON Web Tokens (JWTs) and suggested macaroons offered superior capabilities for fine-grained authorization, particularly in distributed systems. There was also brief discussion about alternative authorization mechanisms like SPIFFE and their relationship to macaroons.
Clean is a new domain-specific language (DSL) built in Lean 4 for formally verifying zero-knowledge circuits. It aims to bridge the gap between circuit development and formal verification by offering a high-level, functional programming style for defining circuits, along with automated proofs of correctness within Lean's powerful theorem prover. Clean compiles to the intermediate representation used by the Circom zk-SNARK toolkit, enabling practical deployment of verified circuits. This approach allows developers to write circuits in a clear, maintainable way, and rigorously prove that these circuits correctly implement the desired logic, enhancing security and trust in zero-knowledge applications. The DSL includes features like higher-order functions and algebraic data types, enabling more expressive and composable circuit design than existing tools.
Several Hacker News commenters praise Clean's innovative approach to verifying zero-knowledge circuits, appreciating its use of Lean4 for formal proofs and its potential to improve the security and reliability of ZK systems. Some express excitement about Lean4's dependent types and metaprogramming capabilities, and how they might benefit the project. Others raise practical concerns, questioning the performance implications of using a theorem prover for this purpose, and the potential difficulty of debugging generated circuits. One commenter questions the comparison to other frameworks like Noir and Arkworks, requesting clarification on the specific advantages of Clean. Another points out the relative nascency of formal verification in the ZK space, emphasizing the need for further development and exploration. A few users also inquire about the tooling and developer experience, wondering about the availability of IDE support and debugging tools for Clean.
"The Blood on the Keyboard" details the often-overlooked human cost of war reporting. Focusing on World War II correspondents, the article highlights the immense psychological toll exacted by witnessing and documenting constant violence, death, and suffering. These journalists, driven by a sense of duty and the need to inform the public, suppressed their trauma and emotions in order to file their stories, often working under perilous conditions with little support. This resulted in lasting psychological scars, including depression, anxiety, and what we now recognize as PTSD, impacting their lives long after the war ended. The article underscores that the news we consume comes at a price, paid not just in ink and paper, but also in the mental and emotional well-being of those who bring us these stories.
HN users discuss the complexities of judging historical figures by modern standards, particularly regarding Woodrow Wilson's racism. Some argue that while Wilson's views were reprehensible, they were common for his time, and judging him solely on that ignores his other contributions. Others counter that his racism had tangible, devastating consequences for Black Americans and shouldn't be excused. Several commenters highlight the selective application of this "presentism" argument, noting it's rarely used to defend figures reviled by the right. The discussion also touches on the role of historical narratives in shaping present-day understanding, and the importance of acknowledging the full scope of historical figures' actions, both good and bad. A few comments delve into specific examples of Wilson's racist policies and their impact.
Cloudflare has open-sourced OPKSSH, a tool that integrates single sign-on (SSO) with SSH, eliminating the need for managing individual SSH keys. OPKSSH achieves this by leveraging OpenID Connect (OIDC) and issuing short-lived SSH certificates signed by a central Certificate Authority (CA). This allows users to authenticate with their existing SSO credentials, simplifying access management and improving security by eliminating static, long-lived SSH keys. The project aims to standardize SSH certificate issuance and validation through a simple, open protocol, contributing to a more secure and user-friendly SSH experience.
HN commenters generally express interest in OpenPubkey but also significant skepticism and concerns. Several raise security implications around trusting a third party for SSH access and the potential for vendor lock-in. Some question the actual benefits over existing solutions like SSH certificates, agent forwarding, or using configuration management tools. Others see potential value in simplifying SSH key management, particularly for less technical users or in specific scenarios like ephemeral cloud instances. There's discussion around key discovery, revocation speed, and the complexities of supporting different identity providers. The closed-source nature of the server-side component is a common concern, limiting self-hosting options and requiring trust in Cloudflare. Several users also mention existing open-source projects with similar goals and question the need for another solution.
The blog post "Entropy Attacks" argues against blindly trusting entropy sources, particularly in cryptographic contexts. It emphasizes that measuring entropy based solely on observed outputs, like those from /dev/random, is insufficient for security. An attacker might manipulate or partially control the supposedly random source, leading to predictable outputs despite seemingly high entropy. The post uses the example of an attacker influencing the timing of network packets to illustrate how seemingly unpredictable data can still be exploited. It concludes by advocating for robust key-derivation functions and avoiding reliance on potentially compromised entropy sources, suggesting deterministic random bit generators (DRBGs) seeded with a high-quality initial seed as a preferable alternative.
The Hacker News comments discuss the practicality and effectiveness of entropy-reduction attacks, particularly in the context of Bernstein's blog post. Some users debate the real-world impact, pointing out that while theoretically interesting, such attacks often rely on unrealistic assumptions like attackers having precise timing information or access to specific hardware. Others highlight the importance of considering these attacks when designing security systems, emphasizing defense-in-depth strategies. Several comments delve into the technical details of entropy estimation and the challenges of accurately measuring it. A few users also mention specific examples of vulnerabilities related to insufficient entropy, like Debian's OpenSSL bug. The overall sentiment suggests that while these attacks aren't always easily exploitable, understanding and mitigating them is crucial for robust security.
This blog post explores the fascinating world of zero-knowledge proofs (ZKPs), focusing on how they can verify computational integrity without revealing any underlying information. The author uses the examples of Sudoku solutions and Super Mario speedruns to illustrate this concept. A ZKP allows someone to prove they know a valid Sudoku solution or a specific sequence of controller inputs for a speedrun without disclosing the actual solution or inputs. The post explains that this is achieved through clever cryptographic techniques that encode the "knowledge" as mathematical relationships, enabling verification of adherence to rules (Sudoku) or game mechanics (Mario) without revealing the strategy or execution. This demonstrates how ZKPs offer a powerful mechanism for trust and verification in various applications, ensuring validity while preserving privacy.
Hacker News users generally praised the clarity and accessibility of the blog post explaining zero-knowledge proofs. Several commenters highlighted the effective use of Sudoku and Mario speedruns as relatable examples, making the complex topic easier to grasp. Some pointed out the post's concise explanation of the underlying cryptographic principles and appreciated the lack of overly technical jargon. One commenter noted the clever use of visually interactive elements within the Sudoku example. There was a brief discussion about different types of zero-knowledge proofs and their applications, with some users mentioning specific use cases like verifiable computation and blockchain technology. A few commenters also offered additional resources for readers interested in delving deeper into the subject.
NIST has chosen HQC (Hamming Quasi-Cyclic) as the fifth and final public-key encryption algorithm to standardize for post-quantum cryptography. HQC, based on code-based cryptography, offers small public key and ciphertext sizes, making it suitable for resource-constrained environments. This selection concludes NIST's multi-year effort to standardize quantum-resistant algorithms, adding HQC alongside the previously announced CRYSTALS-Kyber for general encryption, CRYSTALS-Dilithium, FALCON, and SPHINCS+ for digital signatures. These algorithms are designed to withstand attacks from both classical and quantum computers, ensuring long-term security in a future with widespread quantum computing capabilities.
HN commenters discuss NIST's selection of HQC, expressing surprise and skepticism. Several highlight HQC's vulnerability to side-channel attacks and question its suitability despite its speed advantages. Some suggest SPHINCS+ as a more robust, albeit slower, alternative. Others note the practical implications of the selection, including the need for hybrid approaches and the potential impact on existing systems. The relatively small key and ciphertext sizes of HQC are also mentioned as positive attributes. A few commenters delve into the technical details of HQC and its underlying mathematical principles. Overall, the sentiment leans towards cautious interest in HQC, acknowledging its strengths while emphasizing its vulnerabilities.
The paper "Constant-time coding will soon become infeasible" argues that maintaining constant-time implementations for cryptographic algorithms is becoming increasingly challenging due to evolving hardware and software environments. The authors demonstrate that seemingly innocuous compiler optimizations and speculative execution can introduce timing variability, even in carefully crafted constant-time code. These issues are exacerbated by the complexity of modern processors and the difficulty of fully understanding their intricate behaviors. Consequently, the paper concludes that guaranteeing constant-time execution across different architectures and compiler versions is nearing impossibility, potentially jeopardizing the security of cryptographic implementations relying on this property to prevent timing attacks. They suggest exploring alternative mitigation strategies, such as masking and blinding, as more robust defenses against side-channel vulnerabilities.
HN commenters discuss the implications of the research paper, which suggests constant-time programming will become increasingly difficult due to hardware optimizations like speculative execution. Several express concern about the future of cryptography and security-sensitive code, as these rely heavily on constant-time implementations to prevent side-channel attacks. Some doubt the practicality of the attack described, citing existing mitigations and the complexity of exploiting microarchitectural side channels. Others propose software-based defenses, such as using interpreter-based languages, formal verification, or inserting random delays. The feasibility and cost of deploying these mitigations are also debated, with some arguing that the burden will fall disproportionately on developers. There's also skepticism about the paper's claims of "infeasibility," with commenters suggesting that constant-time coding will become more challenging but not impossible.
This blog post explores how a Certificate Authority (CA) could maliciously issue a certificate with a valid signature but an impossibly distant expiration date, far beyond the CA's own validity period. This "fake future" certificate wouldn't trigger typical browser warnings because the signature checks out. However, by comparing the certificate's notAfter date with Signed Certificate Timestamps (SCTs) from publicly auditable logs, inconsistencies can be detected. These SCTs provide proof of inclusion in a log at a specific time, effectively acting as a timestamp for when the certificate was issued. If the SCT is newer than the CA's validity period but the certificate claims an older issuance date within that validity period, it indicates potential foul play. The post further demonstrates how this discrepancy can be checked programmatically using open-source tools.
Hacker News users discuss the practicality and implications of the blog post's method for detecting malicious Sub-CAs. Several commenters point out the difficulty of implementing this at scale due to the computational cost and potential performance impact of checking every certificate against a large CRL set. Others express concerns about the feasibility of maintaining an up-to-date list of suspect CAs, given their dynamic nature. Some question the overall effectiveness, arguing that sophisticated attackers could circumvent such checks. A few users suggest alternative approaches like using DNSSEC and DANE, or relying on operating system trust stores. The overall sentiment leans toward acknowledging the validity of the author's points while remaining skeptical of the proposed solution's real-world applicability.
Noise Explorer is a web tool for designing and visualizing cryptographic handshake patterns based on the Noise Protocol Framework. It allows users to interactively select pre-defined patterns or create custom ones by specifying initiator and responder actions, such as sending static keys, ephemeral keys, or performing Diffie-Hellman key exchanges. The tool dynamically generates a visual representation of the handshake, showing message flow, key derivation, and the resulting security properties. This aids in understanding the chosen pattern's security implications and facilitates the selection of an appropriate pattern for a given application.
HN users discussed the practicality and novelty of the noise explorer tool. Some found it a helpful visualization for understanding the handshake process in different noise protocols, appreciating its interactive nature and clear presentation. Others questioned its usefulness beyond educational purposes, doubting its applicability to real-world debugging scenarios. There was also a discussion about the complexity of Noise Protocol itself, with some arguing for simpler alternatives and others highlighting Noise's flexibility and security benefits. Finally, some comments explored the potential for future improvements, such as visualizing different handshake patterns simultaneously or incorporating more detailed cryptographic information.
The post "Learn How to Break AES" details a hands-on educational tool for exploring vulnerabilities in simplified versions of the AES block cipher. It provides a series of interactive challenges where users can experiment with various attack techniques, like differential and linear cryptanalysis, against weakened AES implementations. By manipulating parameters like the number of rounds and key size, users can observe how these changes affect the cipher's security and practice applying cryptanalytic methods to recover the encryption key. The tool aims to demystify advanced cryptanalysis concepts by providing a visual and interactive learning experience, allowing users to understand the underlying principles of these attacks and the importance of a full-strength AES implementation.
HN commenters discuss the practicality and limitations of the "block breaker" attack described in the article. Some express skepticism, pointing out that the attack requires specific circumstances and doesn't represent a practical break of AES. Others highlight the importance of proper key derivation and randomness, reinforcing that the attack exploits weaknesses in implementation rather than the AES algorithm itself. Several comments delve into the technical details, discussing the difference between a chosen-plaintext attack and a known-plaintext attack, as well as the specific conditions under which the attack could be successful. The overall consensus seems to be that while interesting, the "block breaker" is not a significant threat to AES security when implemented correctly. Some appreciate the visualization and explanation provided by the article, finding it helpful for understanding block cipher vulnerabilities in general.
This project introduces a JPEG image compression service that incorporates partially homomorphic encryption (PHE) to enable compression on encrypted images without decryption. Leveraging the somewhat homomorphic nature of certain encryption schemes, specifically the Paillier cryptosystem, the service allows for operations like Discrete Cosine Transform (DCT) and quantization on encrypted data. While fully homomorphic encryption remains computationally expensive, this approach provides a practical compromise, preserving privacy while still permitting some image processing in the encrypted domain. The resulting compressed image remains encrypted, requiring the appropriate key for decryption and viewing.
Hacker News users discussed the practicality and novelty of the JPEG compression service using homomorphic encryption. Some questioned the real-world use cases, given the significant performance overhead compared to standard JPEG compression. Others pointed out that the homomorphic encryption only applies to the DCT coefficients and not the entire JPEG pipeline, limiting the actual privacy benefits. The most compelling comments highlighted this limitation, suggesting that true end-to-end encryption would be more valuable but acknowledging the difficulty of achieving that with current homomorphic encryption technology. There was also skepticism about the claimed 10x speed improvement, with requests for more detailed benchmarks and comparisons to existing methods. Some commenters expressed interest in the potential applications, such as privacy-preserving image processing in medical or financial contexts.
Signal's cryptography is generally well-regarded, using established and vetted protocols like X3DH and Double Ratchet for secure messaging. The blog post author reviewed Signal's implementation and found it largely sound, praising the clarity of the documentation and the overall design. While some minor theoretical improvements were suggested, like using a more modern key derivation function (HKDF over SHA-256) and potentially exploring post-quantum cryptography for future-proofing, the author concludes that Signal's current cryptographic choices are robust and secure, offering strong confidentiality and integrity protections for users.
Hacker News users discussed the Signal cryptography review, mostly agreeing with the author's points. Several highlighted the importance of Signal's Double Ratchet algorithm and the trade-offs involved in achieving strong security while maintaining usability. Some questioned the practicality of certain theoretical attacks, emphasizing the difficulty of exploiting them in the real world. Others discussed the value of formal verification efforts and the overall robustness of Signal's protocol design despite minor potential vulnerabilities. The conversation also touched upon the importance of accessible security audits and the challenges of maintaining privacy in messaging apps.
The post "XOR" explores the remarkable versatility of the exclusive-or (XOR) operation in computer programming. It highlights XOR's utility in a variety of contexts, from cryptography (simple ciphers) and data manipulation (swapping variables without temporary storage) to graphics programming (drawing lines and circles) and error detection (parity checks). The author emphasizes XOR's fundamental mathematical properties, like its self-inverting nature (A XOR B XOR B = A) and commutativity, demonstrating how these properties enable elegant and efficient solutions to seemingly complex problems. Ultimately, the post advocates for a deeper appreciation of XOR as a powerful tool in any programmer's arsenal.
HN users discuss various applications and interpretations of XOR. Some highlight its reversibility and use in cryptography, while others explain its role in parity checks and error detection. A few comments delve into its connection with addition and subtraction in binary arithmetic. The thread also explores the efficiency of XOR in comparison to other bitwise operations and its utility in situations requiring toggling, such as graphics programming. Some users share personal anecdotes of using XOR for tasks like swapping variables without temporary storage. A recurring theme is the elegance and simplicity of XOR, despite its power and versatility.
The blog post explores the challenges of establishing trust in decentralized systems, particularly focusing on securely bootstrapping communication between two untrusting parties. It proposes a solution using QUIC and 2-party relays to create a verifiable path of encrypted communication. This involves one party choosing a relay server they trust and communicating that choice (and associated relay authentication information) to the other party. This second party can then, regardless of whether they trust the chosen relay, securely establish communication through the relay using QUIC's built-in cryptographic mechanisms. This setup ensures end-to-end encryption and authenticates both parties, allowing them to build trust and exchange further information necessary for direct peer-to-peer communication, ultimately bypassing the relay.
Hacker News users discuss the complexity and potential benefits of the proposed trust bootstrapping system using 2-party relays and QUIC. Some express skepticism about its practicality and the added overhead compared to existing solutions like DNS and HTTPS. Concerns are raised regarding the reliance on relay operators, potential centralization, and performance implications. Others find the idea intriguing, particularly its potential for censorship resistance and improved privacy, acknowledging that it represents a significant departure from established internet infrastructure. The discussion also touches upon the challenges of key distribution, the suitability of QUIC for this purpose, and the need for robust relay discovery mechanisms. Several commenters highlight the difficulty of achieving true decentralization and the risk of malicious relays. A few suggest alternative approaches like blockchain-based solutions or mesh networking. Overall, the comments reveal a mixed reception to the proposal, with some excitement tempered by pragmatic concerns about its feasibility and security implications.
Latacora's blog post "How (not) to sign a JSON object" cautions against signing JSON by stringifying it before applying a signature. This approach is vulnerable to attacks that modify whitespace or key ordering, which changes the string representation without altering the JSON's semantic meaning. The correct method involves canonicalizing the JSON object first – transforming it into a standardized, consistent byte representation – before signing. This ensures the signature validates only identical JSON objects, regardless of superficial formatting differences. The post uses examples to demonstrate the vulnerabilities of naive stringification and advocates using established JSON Canonicalization Schemes (JCS) for robust and secure signing.
HN commenters largely agree with the author's points about the complexities and pitfalls of signing JSON objects. Several highlighted the importance of canonicalization before signing, with some mentioning specific libraries like JWS and json-canonicalize to ensure consistent formatting. The discussion also touches upon alternatives like JWT (JSON Web Tokens) and COSE (CBOR Object Signing and Encryption) as potentially better solutions, particularly JWT for its ease of use in web contexts. Some commenters delve into the nuances of JSON's flexibility, which can make secure signing difficult, such as varying key order and whitespace handling. A few also caution against rolling your own cryptographic solutions and advocate for using established libraries where possible.
Summary of Comments ( 1 )
https://news.ycombinator.com/item?id=44083753
Hacker News users discuss the practicality and prevalence of elliptic curve cryptography (ECC) versus traditional Diffie-Hellman. Many agree that ECC is dominant in modern applications due to its efficiency and smaller key sizes. Some commenters point out niche uses for traditional Diffie-Hellman, such as in legacy systems or specific protocols where ECC isn't supported. Others highlight the importance of understanding the underlying mathematics of both methods, regardless of which is used in practice. A few express concern over potential vulnerabilities in ECC implementations, particularly regarding patents and potential backdoors. There's also discussion around the learning curve for ECC and resources available for those wanting to deepen their understanding.
The Hacker News post titled "There Is No Diffie-Hellman but Elliptic Curve Diffie-Hellman" generated several comments discussing the nuances of the title and the current state of cryptography.
Several commenters took issue with the provocative title. One commenter pointed out that regular Diffie-Hellman is still used and relevant, particularly in protocols like SSH. They emphasized that while elliptic curve cryptography is becoming increasingly prevalent, declaring traditional Diffie-Hellman obsolete is misleading and inaccurate. Another commenter echoed this sentiment, stating that the title is "clickbaity" and ignores the continued practical applications of finite-field Diffie-Hellman. This commenter further elaborated that dismissing established technologies based solely on the rise of newer alternatives is a flawed approach.
The discussion also delved into the reasons behind the increasing popularity of elliptic curve cryptography. One commenter highlighted the performance advantages of ECC, explaining that it offers comparable security with smaller key sizes, leading to faster computations and reduced bandwidth requirements. They also acknowledged the author's point that ECC is generally preferred in modern implementations.
Another thread of conversation focused on the security implications of different cryptographic algorithms. A commenter mentioned the potential vulnerability of finite-field Diffie-Hellman to attacks from sufficiently powerful quantum computers, while noting that elliptic curve cryptography is also susceptible, albeit to a different type of quantum algorithm. This led to a brief discussion of post-quantum cryptography and the ongoing efforts to develop algorithms resistant to attacks from quantum computers.
One commenter provided a more nuanced perspective on the author's intent, suggesting that the title might be a playful exaggeration aimed at highlighting the dominance of ECC in contemporary cryptographic implementations. They acknowledged the continued existence and occasional use of finite-field Diffie-Hellman but reiterated that ECC has become the de facto standard in most scenarios.
Finally, some commenters offered practical advice. One recommended using a combined approach, employing both finite-field and elliptic curve Diffie-Hellman to maximize compatibility with older systems while benefiting from the enhanced performance and security of ECC. They also mentioned the importance of staying updated on the latest advancements in cryptography to ensure robust and future-proof security measures.