PBC Library Manual 0.5.11 - Stanford Crypto Group

More documents

Recommendations

Info

} Chapter 2. Tutorial 7
Chapter 3. Pairing functions An application should first initialize a pairing object. This causes PBC to setup curves, groups and other mathematical miscellany. After that, elements can be initialized and manipulated for cryptographic operations. Parameters for various pairings are included with the PBC library distribution in the param subdirectory, and some are suitable for cryptographic use. Some programs in the gen subdirectory may be used to generate parameters (see Chapter 7). Also, see the PBC website for many more pairing parameters. Pairings involve three groups of prime order. The PBC library calls them G1, G2, and GT, and calls the order r. The pairing is a bilinear map that takes two elements as input, one from G1 and one from G2, and outputs an element of GT. The elements of G2 are at least as long as G1; G1 is guaranteed to be the shorter of the two. Sometimes G1 and G2 are the same group (i.e. the pairing is symmetric) so their elements can be mixed freely. In this case the pairing_is_symmetric function returns 1. Bilinear pairings are stored in the data type pairing_t. Functions that operate on them start with pairing_. 3.1. Initializing pairings To initialize a pairing from an ASCIIZ string: pairing_t pairing; pairing_init_set_str(pairing, s); // Where s is a char *. The string s holds pairing parameters in a text format. The param subdirectory contains several examples. Alternatively, call: pairing_t pairing; pairing_init_pbc_param(pairing, param); where param is an initialized pbc_param_t (see Chapter 5). int pairing_init_set_str(pairing_t pairing, const char *s) 8
Page 1 and 2: PBC Library Manual 0.5.11 Ben Lynn
Page 3 and 4: Table of Contents Preface .........
Page 5 and 6: Preface The PBC library is a free p
Page 7 and 8: Chapter 1. Installing PBC The first
Page 9 and 10: Chapter 2. Tutorial This chapter wa
Page 11: 2.2. Import/export Chapter 2. Tutor
Page 15 and 16: Chapter 3. Pairing functions Get re
Page 17 and 18: Chapter 4. Element functions Elemen
Page 19 and 20: void element_set0(element_t e) Set
Page 21 and 22: Chapter 4. Element functions z must
Page 23 and 24: Chapter 4. Element functions void e
Page 25 and 26: size_t element_out_str(FILE * strea
Page 27 and 28: int element_length_in_bytes_x_only(
Page 29 and 30: Chapter 5. Param functions Pairings
Page 31 and 32: Chapter 5. Param functions Generate
Page 33 and 34: Chapter 6. Other functions Random n
Page 35 and 36: Reports informational message. void
Page 37 and 38: nd(G) init_pairing_A(); Other sampl
Page 39 and 40: Chapter 8. PBC internals The source
Page 41 and 42: Additionally, defining PBC_DEBUG ca
Page 43 and 44: The lack of an x term simplifies so
Page 45 and 46: Chapter 8. PBC internals b: E: y^2=
Page 47 and 48: Returns the pointer at index i in t
Page 49 and 50: Chapter 8. PBC internals I would li
Page 51: Appendix A. Contributors Ben Lynn w

PBC Library Manual 0.5.11 - Stanford Crypto Group

Create successful ePaper yourself

Delete template?

Save as template?