Data Structures and Algorithms

2007 Submissions

[5] viXra:2007.0194 [pdf] replaced on 2023-05-10 06:02:23

W-OTS# - Shorter and Faster Winternitz Signatures

Authors: Herman Schoenfeld
Comments: 5 Pages.

A very simple modification to the standard W-OTS scheme is presented called W-OTS# that achieves a security enhancement similar to W-OTS+ but without the overhead of hashing a randomization vector in every round of the chaining function. The idea proffered by W-OTS# is to simply thwart Birthday-attacks altogether by signing an HMAC of the message-digest (keyed with cryptographically random salt) rather than the message-digest itself. The signer thwarts a birthday attack by virtue of requiring that the attacker guess the salt bits in addition to the message-digest bits during the collision scanning process. By choosing a salt length matching the message-digest length, the security of W-OTS# reduces to that of the cryptographic hash function. This essentially doubles the security level of W-OTS and facilitates the use of shorter hash functions which provides shorter and faster signatures for same security. For example, W-OTS# 128-bit signatures have commensurate security to standard W-OTS 256-bit signatures yet are roughly half the size and twice as fast. It is proposed that Blake2b-128 and Winternitz parameter w=4 (i.e. base-16 digits) be adopted as the default parameter set for the W-OTS# scheme.
Category: Data Structures and Algorithms

[4] viXra:2007.0143 [pdf] submitted on 2020-07-18 12:35:11

The Blockcard Protocol: It's the Proof-of-Thought That Counts

Authors: Robert S. Adlemir, Robert S. Adlemir, Chris K. Wong
Comments: 5 Pages.

We identify a major security flaw in modern gift transaction protocol that allows for malicious entities to send questionable metadata to insecure1 recipients. To address these weaknesses we introduce the Blockcard protocol, a novel variant of Blockchain technology that uses an asymmetric proof-of-work CPU cost function over payload metadata to provide a cryptographically secure and efficient method of verifying that gift-givers thought enough about the recipients payload or lack thereof for it to count. This has the advantage of making it computationally infeasible and socially awkward for adversarial gift-givers to double-spend, spoof, or precompute their celebratory thoughts.
Category: Data Structures and Algorithms

[3] viXra:2007.0082 [pdf] submitted on 2020-07-13 10:58:50

Throw2goto: an Exception Handling Optimization

Authors: Jeff Linahan
Comments: 5 Pages.

We discuss an exception handling optimization that achieves zero overhead in both space and time compared to ordinary C-style error handling control flow when the compiler can see which catch block a given throw expression will land in. The technique brings exceptions more in line with the design goals of C++, reducing the need for alternate error handling mechanisms.
Category: Data Structures and Algorithms

[2] viXra:2007.0063 [pdf] replaced on 2020-08-07 10:34:35

Is it Still Worth the Cost to Teach Compiling in 2020 ? a Pedagogical Experience Through Hortensias Compiler and Virtual Machine

Authors: Karim Baina, Boualem Benatallah
Comments: 20 Pages.

With the disruption produced by extensive automation of automation due to advanced research in machine learning, and auto machine learning, even in programming language translation, the main goal of this paper is to discuss the following question "Is it still worth the cost to teach compiling in 2020 ?". Our paper defends the "Yes answer" within software engineering majors. The paper also shares the experience of teaching compiling techniques course best practices since more than 15 years, presents and evaluates this experience through Hortensias, a pedagogical compiling laboratory platform providing a language compiler and a virtual machine. Hortensias is a multilingual pedagogical platform for learning end teaching how to build compilers front and back-end. Hortensias language offers the possibility to the programmer to customise the compiler associativity management, visualise the intermediary representations of compiled code, or customise the optimisation management, and the error management language for international students communities. Hortensias offers the possibility to the beginner programmer to use a graphical user interface to program by clicking. Hortensias compiling pedagogy evaluation has been conducted through two surveys involving in a voluntarily basis engineering students and alumni during one week. It targeted two null hypothesis : the first null hypothesis supposes that compiling teaching is becoming outdated with regards to current curricula evolution, and the second null hypothesis supposes Hortensias compiling based pedagogy has no impact neither on understanding nor on implementing compilers and interpreters. During fifteen years of teaching compiler engineering, Hortensias was a wonderful pedagogic experiment either for teaching and for learning, since vulgarising abstract concepts becomes very easier for teachers, lectures follow a gamification-like approach, and students become efficient in delivering versions of their compiler software product in a fast pace.
Category: Data Structures and Algorithms

[1] viXra:2007.0008 [pdf] submitted on 2020-07-01 12:58:38

A Polynomial Time Algorithm for Sat

Authors: Ortho Flint
Comments: 3 Pages.

The deterministic polynomial time algorithm that determines satisfiability of 3-SAT can be generalized for SAT.
Category: Data Structures and Algorithms