BitPunch McEliece v0.0.4

Introduction

Goal of BitPunch project is to make a standalone McEliece implementation. Current version is only develompent version, it is not suitable to use in real-life implementation. Our implementation of MECS uses Goppa codes. For ASN.1 we are using libtasn1 library (tested with version 3.4-3).

• in Debian based distro install package:
  • apt-get install libtasn1-6 libtasn1-6-dev

I know, there is a lot of BUGS now. If you have any questions, ideas create new issue or contact me:

• xuhreckyf [ you know what to put here ] stuba.sk

Where are the most important processes done?

• Initialization:
  • lib/src/bitpunch/crypto/mecsctx.h
    • BPU_mecsInitCtx()
    • BPU_codeInitCtx()
    • BPU_mathInitCtx()
• Encryption/Decryption:
  • lib/src/bitpunch/crypto/mecsbasic/mecsbasic.h
    • BPU_mecsBasicEncrypt()
    • BPU_mecsBasicDecrypt()
  • lib/src/bitpunch/crypto/cca2/mecspointcheval.h
    • BPU_mecsPointchevalCCA2Encrypt()
    • BPU_mecsPointchevalCCA2Decrypt()
• KeyGen:
  • lib/src/bitpunch/code/goppa/goppa.h
    • BPU_goppaGenCode()
• Encode/Decode:
  • lib/src/bitpunch/code/goppa/goppa.h
    • BPU_goppaEncode()
    • BPU_goppaDecode()

Structure

Here is the basic structure overview.

Convention

Current version: 0.0.3

• function name format: BPU_thisFunctionMakesMeDead
• data types name format: BPU_T_This_Data_Type_Rocks
• variable name format: four_your_information
• all data types has prefix BPU_T_*
• data types has also prefix, which are working with some general types:
  • BPU_T_GF2_*
  • BPU_T_GF2_16x_*
• enumeration data types BPU_T_EN_* -enumeration etries BPU_EN_*
• unoin data types BPU_T_UN_*

error codes definitions BPU_EC_*

• all functions, macros has prefix BPU_*
  • there is also specific prefix for functions, which are working with kind of data:
    • BPU_gf2Vec*
    • BPU_gf2xVec*
    • BPU_gf2xPoly*
    • BPU_gf2Mat*
    • BPU_gf2xMat*
    • BPU_perm*
    • BPU_code*
    • BPU_goppa*
    • BPU_mecs*
    • BPU_math*
    • BPU_pad*
    • BPU_prng*
• print functions stating with prefix: -BPU_print*

Modules

BitPunch has more modules, all sources are located in lib/src/bitpunch/:

• asn1
  • is used for searializing key using libtasn1 (tested with version 3.4-3)

it uses DER encoding

• math

contains all arithmetic operation over GF2, GF2x, polynomials, Matrices, Vectors, Permutations, ...

• code

implements code matters, here you can specify your own codes

• goppa

crypto

• implements cryptosystem matters
• mecsbasic, padding

prng

• interface for PRNG

Contexts

There are 3 contexts:

• Mecs context
  • this context registers encrypt, decrypt and key generation functions
• Code context
  • this context registers encode, decode and code generation functions
• Math context
  • speed up math operations over GF2x When you want to use MECS you just need to initialize context, using BPU_mecsInitCtx, see doc for more details.

Build

For build details go to lib/ and see makefile help. Now you can build test aplication, realease or debug, you can specify wheter you want to use precomputed H matrix (more memory) or not:

• make help - it is make help
• make print-info - info where is your aplication
• make test - with H matrix
• make test-debug - with H matrix
• make test-wo-h - without H matrix
• make test-with-debug - without H matrix
• make static - to build static lib
• make shared - to build shared lib

Builded libraries are located in dist/ folder. For more preprocesor options see lib/src/bitpunch/config.h file. Default optimization is -O2. To set up more verbosity define -DERRORL, -DWARNING_L or DDEBUG_L, this are using functions like BPU_printError(), BPU_printWarning(), BPU_printDebug().