Efficient hash maps to G2 on BLS curves
When a pairing e:G1×G2→GT, on an elliptic curve E defined over a finite field Fq, is exploited for an identity-based protocol, there is often the need to hash binary strings into G1 and G2. Traditionally, if E admits a twist E~ of order d, then G1=E(Fq)∩E[r], where r is a prime integer, and G2=E~(Fq...
| Main Authors: | , |
|---|---|
| Format: | Journal article |
| Language: | English |
| Published: |
Springer
2020
|
| _version_ | 1797106801424990208 |
|---|---|
| author | Budroni, A Pintore, F |
| author_facet | Budroni, A Pintore, F |
| author_sort | Budroni, A |
| collection | OXFORD |
| description | When a pairing e:G1×G2→GT, on an elliptic curve E defined over a finite field Fq, is exploited for an identity-based protocol, there is often the need to hash binary strings into G1 and G2. Traditionally, if E admits a twist E~ of order d, then G1=E(Fq)∩E[r], where r is a prime integer, and G2=E~(Fqk/d)∩E~[r], where k is the embedding degree of E w.r.t. r. The standard approach for hashing into G2 is to map to a general point P∈E~(Fqk/d) and then multiply it by the cofactor c=#E~(Fqk/d)/r. Usually, the multiplication by c is computationally expensive. In order to speed up such a computation, two different methods—by Scott et al. (International conference on pairing-based cryptography. Springer, Berlin, pp 102–113, 2009) and by Fuentes-Castaneda et al. (International workshop on selected areas in cryptography)—have been proposed. In this paper we consider these two methods for BLS pairing-friendly curves having k∈{12,24,30,42,48}, providing efficiency comparisons. When k=42,48, the application of Fuentes et al. method requires expensive computations which were infeasible for the computational power at our disposal. For these cases, we propose hashing maps that we obtained following Fuentes et al. idea. |
| first_indexed | 2024-03-07T07:07:37Z |
| format | Journal article |
| id | oxford-uuid:54fc3f75-d451-4402-bf68-8077f5b56493 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T07:07:37Z |
| publishDate | 2020 |
| publisher | Springer |
| record_format | dspace |
| spelling | oxford-uuid:54fc3f75-d451-4402-bf68-8077f5b564932022-05-18T08:39:08ZEfficient hash maps to G2 on BLS curvesJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:54fc3f75-d451-4402-bf68-8077f5b56493EnglishSymplectic ElementsSpringer2020Budroni, APintore, FWhen a pairing e:G1×G2→GT, on an elliptic curve E defined over a finite field Fq, is exploited for an identity-based protocol, there is often the need to hash binary strings into G1 and G2. Traditionally, if E admits a twist E~ of order d, then G1=E(Fq)∩E[r], where r is a prime integer, and G2=E~(Fqk/d)∩E~[r], where k is the embedding degree of E w.r.t. r. The standard approach for hashing into G2 is to map to a general point P∈E~(Fqk/d) and then multiply it by the cofactor c=#E~(Fqk/d)/r. Usually, the multiplication by c is computationally expensive. In order to speed up such a computation, two different methods—by Scott et al. (International conference on pairing-based cryptography. Springer, Berlin, pp 102–113, 2009) and by Fuentes-Castaneda et al. (International workshop on selected areas in cryptography)—have been proposed. In this paper we consider these two methods for BLS pairing-friendly curves having k∈{12,24,30,42,48}, providing efficiency comparisons. When k=42,48, the application of Fuentes et al. method requires expensive computations which were infeasible for the computational power at our disposal. For these cases, we propose hashing maps that we obtained following Fuentes et al. idea. |
| spellingShingle | Budroni, A Pintore, F Efficient hash maps to G2 on BLS curves |
| title | Efficient hash maps to G2 on BLS curves |
| title_full | Efficient hash maps to G2 on BLS curves |
| title_fullStr | Efficient hash maps to G2 on BLS curves |
| title_full_unstemmed | Efficient hash maps to G2 on BLS curves |
| title_short | Efficient hash maps to G2 on BLS curves |
| title_sort | efficient hash maps to g2 on bls curves |
| work_keys_str_mv | AT budronia efficienthashmapstog2onblscurves AT pintoref efficienthashmapstog2onblscurves |