Concrete
WebsiteLibrariesProducts & ServicesDevelopersSupport
2.10
2.10
  • Welcome
  • Get Started
    • What is Concrete?
    • Installation
    • Quick start
    • Quick overview
    • Terminology
  • Operations
    • Table Lookups basics
    • Non-linear operations
    • Other operations
      • Bit extraction
      • Common tips
      • Extensions
  • Compilation
    • Combining compiled functions
      • With composition
      • With modules
    • Key-related options for faster execution
      • Multi precision
      • Multi parameters
    • Compression
    • Reusing arguments
    • Parameter compatibility with restrictions
    • Common errors
  • Execution / Analysis
    • Simulation
    • Debugging and artifact
    • Performance
    • GPU acceleration
    • Other
      • Statistics
      • Progressbar
      • Formatting and drawing
  • Guides
    • Configure
    • Manage keys
    • Deploy
    • TFHE-rs Interoperability
      • Shared key
      • Serialization
    • Optimization
      • Improve parallelism
        • Dataflow parallelism
        • Tensorizing operations
      • Optimize table lookups
        • Reducing TLU
        • Implementation strategies
        • Round/truncating
        • Approximate mode
        • Bit extraction
      • Optimize cryptographic parameters
        • Error probability
        • Composition
  • Tutorials
    • See all tutorials
    • Part I: Concrete - FHE compiler
    • Part II: The Architecture of Concrete
  • References
    • API
    • Supported operations
  • Explanations
    • Compiler workflow
    • Advanced features
      • Table Lookups advanced
      • Rounding
      • Truncating
      • Floating points
      • Comparisons
      • Min/Max operations
      • Bitwise operations
      • Direct circuits
      • Tagging
    • Cryptography basics
    • Security
    • Frontend fusing
  • Developers
    • Contributing
      • Project layout
      • Compiler backend
        • Adding a new backend
      • Optimizer
      • MLIR FHE dialects
        • FHELinalg dialect
        • FHE dialect
        • TFHE dialect
        • Concrete dialect
        • Tracing dialect
        • Runtime dialect
        • SDFG dialect
      • Call FHE circuits from other languages
      • Benchmarking
      • Examples
      • Making a release
    • Release note
    • Feature request
    • Bug report
Powered by GitBook

Libraries

  • TFHE-rs
  • Concrete
  • Concrete ML
  • fhEVM

Developers

  • Blog
  • Documentation
  • Github
  • FHE resources

Company

  • About
  • Introduction to FHE
  • Media
  • Careers
On this page

Was this helpful?

Export as PDF
  1. Guides
  2. Optimization
  3. Optimize table lookups

Approximate mode

PreviousRound/truncatingNextBit extraction

Last updated 1 month ago

Was this helpful?

This guide teaches how to improve the execution time of Concrete circuits by using approximate mode for rounding.

You can enable to gain even more performance when using rounding by sacrificing some more exactness:

import numpy as np
from concrete import fhe

inputset = fhe.inputset(fhe.uint10)
for lsbs_to_remove in range(0, 10):
    def f(x):
        return fhe.round_bit_pattern(x, lsbs_to_remove, exactness=fhe.Exactness.APPROXIMATE) // 2

    compiler = fhe.Compiler(f, {"x": "encrypted"})
    circuit = compiler.compile(inputset)

    print(f"{lsbs_to_remove=} -> {int(circuit.complexity):>13_} complexity")

prints:

lsbs_to_remove=0 -> 9_134_406_574 complexity
lsbs_to_remove=1 -> 5_548_275_712 complexity
lsbs_to_remove=2 -> 2_430_793_927 complexity
lsbs_to_remove=3 -> 1_058_638_119 complexity
lsbs_to_remove=4 ->   409_952_712 complexity
lsbs_to_remove=5 ->   172_138_947 complexity
lsbs_to_remove=6 ->    99_198_195 complexity
lsbs_to_remove=7 ->    71_644_380 complexity
lsbs_to_remove=8 ->    55_860_516 complexity
lsbs_to_remove=9 ->    50_978_148 complexity
approximate mode