diffsquare

From the Author

Created by Abhrankan Chakrabarti, this project implements an efficient version of Fermat’s Difference of Squares method for factoring large integers. Written in Rust, it leverages the malachite crate for high-performance arbitrary-precision arithmetic.

Recent Update – v0.9.0

🧮 Persistent interactive mode

When diffsquare is run without any flags or piped input, it now enters a continuous interactive loop.
After each factorization, it prompts again for a new modulus.
To exit the loop, the user can type exit or quit.
Designed for exploratory usage, teaching, and manual testing.
Fully compatible with all previous interactive features.

Key Features

diffsquare is a fast and lightweight CLI utility for factoring large integers using Fermat’s Difference of Squares method.

Efficient Fermat’s Difference of Squares factorization.
Parallelized using rayon for faster factorization on multi-core systems (since v0.5.0).
Optional file input for batch factorization (--input) (new in v0.7.0).
Optional file output with --output to save results (since v0.6.0).
Control thread count for batch processing with --threads (new in v0.7.0).
Progress bar for file and stdin batch input (new in v0.7.0).
Optional --timeout N to limit maximum time per factorization in milliseconds (since v0.6.1).
CSV output support via --csv flag (since v0.6.1).
JSON output mode (--json) for scripting and automation (since v0.3.0).
Quiet mode (-q) disables prompts and hides intermediate output — ideal for scripting.
--time-only flag for showing only execution time — useful for benchmarking (since v0.3.1).
Batch factorization via --stdin (since v0.4.0).
Support for decimal, hexadecimal, and scientific notation input.
Command-line interface with interactive fallback.
Optional control over iteration starting point (--iter) and precision (--prec).
Scientific notation used in verbose mode for large integer readability.
Execution time displayed after successful factorization.

GitHub Repository: diffsquare

Installation

Install via Cargo:

cargo install diffsquare

Ensure $HOME/.cargo/bin is in your PATH:

export PATH="$HOME/.cargo/bin:$PATH"

Build Instructions

To build from source manually:

git clone https://github.com/Abhrankan-Chakrabarti/diffsquare.git
cd diffsquare
cargo build --release

🔧 Usage Examples

Run diffsquare interactively or use flags for automation:

# 🔹 Fully interactive: prompts for modulus
diffsquare

# 🔹 Provide a decimal modulus
diffsquare -n 179769313486231590772930519078902473361797697894230657273430081157732675805505620686985379449212982959585501387537164015710139858647833778606925583497541085196591615128057575940752635007475935288710823649949940771895617054361149474865046711015101563940680527540071584560878577663743040086340742855278549092581

# 🔹 Provide a hexadecimal modulus
diffsquare -n 0xDEADBEEFCAFEBABE1234567890

# 🔹 Specify starting iteration
diffsquare -n 0xC0FFEE123456789 -i 1000000

# 🔹 Use custom precision for verbose scientific output
diffsquare -n 0xABCD1234 -p 30

# 🔹 Quiet mode, suppress intermediate output
diffsquare -n 0xCAFED00D1234 -q

# 🔹 JSON output for scripting
diffsquare -n 0xC0FFEE123456789 --json

# 🔹 Show only execution time (for benchmarking)
diffsquare -n 0xCAFED00D1234 --time-only

# 🔹 Factor 2^32 + 1 (Fermat number F5) from piped input
echo "2^32 + 1" | bc | diffsquare

# 🔹 Batch factorization from stdin
echo -e "2761929023323646159\n3189046231347719467" | diffsquare --stdin

# 🔹 Batch factorization from file input
diffsquare --input numbers.txt

# 🔹 Batch with threads and JSON output
diffsquare --input numbers.txt --threads 4 --json

# 🔹 Batch with CSV output and save to file
diffsquare --input numbers.txt --csv --output results.csv

Command-Line Flags

Short	Long	Description
`-n`	`--mod`	Number to factor (supports `0x` for hex or scientific notation)
`-i`	`--iter`	Starting iteration value
`-p`	`--prec`	Precision for verbose scientific output
`-q`	`--quiet`	Suppress prompts and intermediate output
	`--json`	Output result in JSON format
	`--csv`	Output result as CSV
	`--time-only`	Show only execution time
	`--stdin`	Read newline-separated input from stdin
	`--input`	Read newline-separated input from file
	`--threads`	Number of threads for batch factorization (`--stdin` / `--input`) (default: logical CPUs)
	`--output`	Output results to file
	`--timeout`	Timeout in milliseconds for each factorization
`-h`	`--help`	Show usage help
`-v`	`--version`	Show version