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author | 2015-11-23 17:48:48 +0100 | |
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committer | 2015-11-23 17:48:48 +0100 | |
commit | fca74d4bc3569506a6659880a89aa009dc11f552 (patch) | |
tree | 4cefd06af989608ea8ebd3bc6306889e2a1ad175 /moon-abe/pbc-0.5.14/doc/pairingfns.txt | |
parent | 840ac3ebca7af381132bf7e93c1e4c0430d6b16a (diff) |
moon-abe cleanup
Change-Id: Ie1259856db03f0b9e80de3e967ec6bd1f03191b3
Diffstat (limited to 'moon-abe/pbc-0.5.14/doc/pairingfns.txt')
-rw-r--r-- | moon-abe/pbc-0.5.14/doc/pairingfns.txt | 69 |
1 files changed, 0 insertions, 69 deletions
diff --git a/moon-abe/pbc-0.5.14/doc/pairingfns.txt b/moon-abe/pbc-0.5.14/doc/pairingfns.txt deleted file mode 100644 index 4ea4bf13..00000000 --- a/moon-abe/pbc-0.5.14/doc/pairingfns.txt +++ /dev/null @@ -1,69 +0,0 @@ -== 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 -<<bundlechap>>). 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_+. - -=== 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 <<paramchap>>). - -include::gen/pairing_init.txt[] - -=== Applying pairings === - -The function `pairing_apply` can be called to apply a bilinear map. The order -of the inputs is important. The first, which holds the output, must be from the -group GT. The second must be from G1, the third from G2, and the fourth must be -the +pairing_t+ variable that relates them. - -In some applications, the programmer may know that many pairings with the same -G1 input will be computed. If so, preprocessing should be used to avoid -repeating many calculations saving time in the long run. A variable of type -+pairing_pp_t+ should be declared, initialized with the fixed G1 element, and -then used to compute pairings: - - pairing_pp_t pp; - pairing_pp_init(pp, x, pairing); // x is some element of G1 - pairing_pp_apply(r1, y1, pp); // r1 = e(x, y1) - pairing_pp_apply(r2, y2, pp); // r2 = e(x, y2) - pairing_pp_clear(pp); // don't need pp anymore - -Never mix and match G1, G2, and GT groups from different pairings. - -include::gen/pairing_apply.txt[] - -=== Other pairing functions === - -include::gen/pairing_op.txt[] |