Safra, Muli (Shmuel) Mathematics of computation through the lens of linear equations and lattices. (English) Zbl 07821717 Beliaev, Dmitry (ed.) et al., International congress of mathematicians 2022, ICM 2022, Helsinki, Finland, virtual, July 6–14, 2022. Volume 6. Sections 12–14. Berlin: European Mathematical Society (EMS). 4914-4969 (2023). MSC: 03D15 11H06 11P21 52C07 68W25 11D04 PDFBibTeX XMLCite \textit{M. Safra}, in: International congress of mathematicians 2022, ICM 2022, Helsinki, Finland, virtual, July 6--14, 2022. Volume 6. Sections 12--14. Berlin: European Mathematical Society (EMS). 4914--4969 (2023; Zbl 07821717) Full Text: DOI OA License
Omar, Sami; Eid, Abdulla On elliptic curve \(L\)-functions integrated encryption scheme. (English) Zbl 07819361 Grześkowiak, Maciej (ed.) et al., Number-theoretic methods in cryptology, NuTMiC 22. Selected papers based on the presentations at the 3rd conference, Poznań, Poland, August 2022. Warsaw: Polish Academy of Sciences, Institute of Mathematics. Banach Cent. Publ. 126, 53-72 (2023). MSC: 94A60 42A16 11G05 11T71 14G50 14H52 PDFBibTeX XMLCite \textit{S. Omar} and \textit{A. Eid}, Banach Cent. Publ. 126, 53--72 (2023; Zbl 07819361) Full Text: DOI
Sălăgean, Ana; Reyes-Paredes, Percy Probabilistic estimation of the algebraic degree of Boolean functions. (English) Zbl 07778090 Cryptogr. Commun. 15, No. 6, 1199-1215 (2023). MSC: 94D10 94A60 11T06 PDFBibTeX XMLCite \textit{A. Sălăgean} and \textit{P. Reyes-Paredes}, Cryptogr. Commun. 15, No. 6, 1199--1215 (2023; Zbl 07778090) Full Text: DOI arXiv OA License
Zahhafi, Leila; Khadir, Omar A DSA-like digital signature protocol. (English) Zbl 1498.94096 J. Discrete Math. Sci. Cryptography 25, No. 6, 1705-1716 (2022). MSC: 94A62 94A60 11T71 PDFBibTeX XMLCite \textit{L. Zahhafi} and \textit{O. Khadir}, J. Discrete Math. Sci. Cryptography 25, No. 6, 1705--1716 (2022; Zbl 1498.94096) Full Text: DOI arXiv
Hakuta, Keisuke; Ochiai, Hiroyuki; Takagi, Tsuyoshi Comments on efficient batch verification test for digital signatures based on elliptic curves. (English) Zbl 1487.11061 Math. Slovaca 72, No. 3, 575-590 (2022). MSC: 11G20 11T71 11A63 14G50 94A60 PDFBibTeX XMLCite \textit{K. Hakuta} et al., Math. Slovaca 72, No. 3, 575--590 (2022; Zbl 1487.11061) Full Text: DOI
Emura, Keita; Takayasu, Atsushi; Watanabe, Yohei Efficient identity-based encryption with hierarchical key-insulation from HIBE. (English) Zbl 1482.94048 Des. Codes Cryptography 89, No. 10, 2397-2431 (2021). Reviewer: Manish Kumar (Hyderabad) MSC: 94A60 11T71 PDFBibTeX XMLCite \textit{K. Emura} et al., Des. Codes Cryptography 89, No. 10, 2397--2431 (2021; Zbl 1482.94048) Full Text: DOI
Bhattacharjee, Arghya; López, Cuauhtemoc Mancillas; List, Eik; Nandi, Mridul The Oribatida v1.3 family of lightweight authenticated encryption schemes. (English) Zbl 1468.94393 J. Math. Cryptol. 15, 305-344 (2021). MSC: 94A60 94A62 11T06 11T71 11Y16 PDFBibTeX XMLCite \textit{A. Bhattacharjee} et al., J. Math. Cryptol. 15, 305--344 (2021; Zbl 1468.94393) Full Text: DOI
Zhao, Xiaopeng; Cao, Zhenfu; Dong, Xiaolei; Shao, Jun Extended Galbraith’s test on the anonymity of IBE schemes from higher residuosity. (English) Zbl 1481.94129 Des. Codes Cryptography 89, No. 2, 241-253 (2021). MSC: 94A60 11T71 11A15 PDFBibTeX XMLCite \textit{X. Zhao} et al., Des. Codes Cryptography 89, No. 2, 241--253 (2021; Zbl 1481.94129) Full Text: DOI
Di Crescenzo, Giovanni; Khodjaeva, Matluba; Kahrobaei, Delaram; Shpilrain, Vladimir Delegating a product of group exponentiations with application to signature schemes. (English) Zbl 1464.94034 J. Math. Cryptol. 14, 438-459 (2020). MSC: 94A60 94A62 11T71 PDFBibTeX XMLCite \textit{G. Di Crescenzo} et al., J. Math. Cryptol. 14, 438--459 (2020; Zbl 1464.94034) Full Text: DOI
Campello, Antonio; Ling, Cong Random algebraic lattices and codes for wireless communications. (English) Zbl 1484.11154 Beresnevich, Victor (ed.) et al., Number theory meets wireless communications. Based on lectures given at the workshop on interactions between number theory and wireless communication, York, UK, July 4–16, 2016. Cham: Springer. Math. Eng. (Cham), 143-177 (2020). MSC: 11H71 94A05 94A40 PDFBibTeX XMLCite \textit{A. Campello} and \textit{C. Ling}, in: Number theory meets wireless communications. Based on lectures given at the workshop on interactions between number theory and wireless communication, York, UK, July 4--16, 2016. Cham: Springer. 143--177 (2020; Zbl 1484.11154) Full Text: DOI
Selvakumar, R.; Kumar, C. Pavan Concatenated kernel codes. (English) Zbl 1469.94173 Discrete Math. Algorithms Appl. 12, No. 3, Article ID 2050044, 7 p. (2020). MSC: 94B60 11T71 PDFBibTeX XMLCite \textit{R. Selvakumar} and \textit{C. P. Kumar}, Discrete Math. Algorithms Appl. 12, No. 3, Article ID 2050044, 7 p. (2020; Zbl 1469.94173) Full Text: DOI
Di Crescenzo, Giovanni; Khodjaeva, Matluba; Kahrobaei, Delaram; Shpilrain, Vladimir Efficient and secure delegation of exponentiation in general groups to a single malicious server. (English) Zbl 1488.94083 Math. Comput. Sci. 14, No. 3, 641-656 (2020). MSC: 94A60 11T71 PDFBibTeX XMLCite \textit{G. Di Crescenzo} et al., Math. Comput. Sci. 14, No. 3, 641--656 (2020; Zbl 1488.94083) Full Text: DOI Link
Nandi, Mridul; Pandit, Tapas Predicate signatures from pair encodings via dual system proof technique. (English) Zbl 1457.94167 J. Math. Cryptol. 13, No. 3-4, 197-228 (2019). MSC: 94A60 94A62 11T71 14G50 PDFBibTeX XMLCite \textit{M. Nandi} and \textit{T. Pandit}, J. Math. Cryptol. 13, No. 3--4, 197--228 (2019; Zbl 1457.94167) Full Text: DOI
Maxwell, Gregory; Poelstra, Andrew; Seurin, Yannick; Wuille, Pieter Simple Schnorr multi-signatures with applications to bitcoin. (English) Zbl 1419.94043 Des. Codes Cryptography 87, No. 9, 2139-2164 (2019). MSC: 94A60 11T71 PDFBibTeX XMLCite \textit{G. Maxwell} et al., Des. Codes Cryptography 87, No. 9, 2139--2164 (2019; Zbl 1419.94043) Full Text: DOI
Cheraghchi, Mahdi Nearly optimal robust secret sharing. (English) Zbl 1425.94053 Des. Codes Cryptography 87, No. 8, 1777-1796 (2019). MSC: 94A60 11T71 PDFBibTeX XMLCite \textit{M. Cheraghchi}, Des. Codes Cryptography 87, No. 8, 1777--1796 (2019; Zbl 1425.94053) Full Text: DOI
Shikata, Junji; Watanabe, Yohei Identity-based encryption with hierarchical key-insulation in the standard model. (English) Zbl 1455.94192 Des. Codes Cryptography 87, No. 5, 1005-1033 (2019). MSC: 94A60 11T71 PDFBibTeX XMLCite \textit{J. Shikata} and \textit{Y. Watanabe}, Des. Codes Cryptography 87, No. 5, 1005--1033 (2019; Zbl 1455.94192) Full Text: DOI
Guselev, A. M. Application of the lattice theory to the analysis of digital signature schemes. (Russian. English summary) Zbl 1475.94179 Mat. Vopr. Kriptografii 9, No. 4, 73-84 (2018). MSC: 94A62 11H06 PDFBibTeX XMLCite \textit{A. M. Guselev}, Mat. Vopr. Kriptografii 9, No. 4, 73--84 (2018; Zbl 1475.94179) Full Text: DOI MNR
Chatterjee, Sanjit; Prem Laxman Das, M.; Kabaleeshwaran, R. Converting pairing-based cryptosystems from composite to prime order setting – a comparative analysis. (English) Zbl 1401.94142 J. Math. Cryptol. 12, No. 3, 159-190 (2018). MSC: 94A60 11T71 68P25 PDFBibTeX XMLCite \textit{S. Chatterjee} et al., J. Math. Cryptol. 12, No. 3, 159--190 (2018; Zbl 1401.94142) Full Text: DOI
Goswami, Pinkimani; Singh, Madan Mohan; Bhuyan, Bubu A new public key cryptosystem over \(\mathbb Z_{n^2}^\ast\). (English) Zbl 1407.94113 Discrete Math. Algorithms Appl. 9, No. 6, Article ID 1750080, 11 p. (2017). MSC: 94A60 11Y05 11T71 PDFBibTeX XMLCite \textit{P. Goswami} et al., Discrete Math. Algorithms Appl. 9, No. 6, Article ID 1750080, 11 p. (2017; Zbl 1407.94113) Full Text: DOI
Fan, Xinxin; Otemissov, Adilet; Sica, Francesco; Sidorenko, Andrey Multiple point compression on elliptic curves. (English) Zbl 1376.94033 Des. Codes Cryptography 83, No. 3, 565-588 (2017). MSC: 94A60 14G50 11T71 PDFBibTeX XMLCite \textit{X. Fan} et al., Des. Codes Cryptography 83, No. 3, 565--588 (2017; Zbl 1376.94033) Full Text: DOI
Poulakis, Dimitrios New lattice attacks on DSA schemes. (English) Zbl 1408.94960 J. Math. Cryptol. 10, No. 2, 135-144 (2016). MSC: 94A60 11T71 11Y16 PDFBibTeX XMLCite \textit{D. Poulakis}, J. Math. Cryptol. 10, No. 2, 135--144 (2016; Zbl 1408.94960) Full Text: DOI
Bellini, Emanuele; Murru, Nadir An efficient and secure RSA-like cryptosystem exploiting Rédei rational functions over conics. (English) Zbl 1339.94036 Finite Fields Appl. 39, 179-194 (2016). MSC: 94A60 11T71 PDFBibTeX XMLCite \textit{E. Bellini} and \textit{N. Murru}, Finite Fields Appl. 39, 179--194 (2016; Zbl 1339.94036) Full Text: DOI arXiv
Damgård, Ivan; Mikkelsen, Gert Læssøe; Skeltved, Tue On the security of distributed multiprime RSA. (English) Zbl 1457.94118 Lee, Jooyoung (ed.) et al., Information security and cryptology – ICISC 2014. 17th international conference, Seoul, South Korea, December 3–5, 2014. Revised selected papers. Cham: Springer. Lect. Notes Comput. Sci. 8949, 18-33 (2015). MSC: 94A60 11Y05 11T71 PDFBibTeX XMLCite \textit{I. Damgård} et al., Lect. Notes Comput. Sci. 8949, 18--33 (2015; Zbl 1457.94118) Full Text: DOI
Chin, Ji-Jian; Tan, Syh-Yuan; Heng, Swee-Huay; Phan, Raphael C.-W.; Behnia, Rouzbeh A provable secure pairing-free certificateless identification scheme. (English) Zbl 1357.94064 Int. J. Comput. Math. 92, No. 8, 1520-1535 (2015). MSC: 94A60 94A62 14G50 11T71 PDFBibTeX XMLCite \textit{J.-J. Chin} et al., Int. J. Comput. Math. 92, No. 8, 1520--1535 (2015; Zbl 1357.94064) Full Text: DOI
Wang, Baocang Preimage selective trapdoor function: how to repair an easy problem. (English) Zbl 1407.94158 Math. Probl. Eng. 2014, Article ID 475678, 18 p. (2014). MSC: 94A60 11Y16 PDFBibTeX XMLCite \textit{B. Wang}, Math. Probl. Eng. 2014, Article ID 475678, 18 p. (2014; Zbl 1407.94158) Full Text: DOI
Sepahi, Reza; Steinfeld, Ron; Pieprzyk, Josef Lattice-based completely non-malleable public-key encryption in the standard model. (English) Zbl 1342.94095 Des. Codes Cryptography 71, No. 2, 293-313 (2014). MSC: 94A60 11T71 PDFBibTeX XMLCite \textit{R. Sepahi} et al., Des. Codes Cryptography 71, No. 2, 293--313 (2014; Zbl 1342.94095) Full Text: DOI
Shim, Kyung-Ah A strong designated verifier signature scheme tightly related to the LRSW assumption. (English) Zbl 1278.94060 Int. J. Comput. Math. 90, No. 2, 163-171 (2013). MSC: 94A60 11T71 14G50 94A62 PDFBibTeX XMLCite \textit{K.-A. Shim}, Int. J. Comput. Math. 90, No. 2, 163--171 (2013; Zbl 1278.94060) Full Text: DOI
Bibak, Khodakhast Additive combinatorics: with a view towards computer science and cryptography – an exposition. (English) Zbl 1303.11022 Borwein, Jonathan M. (ed.) et al., Number theory and related fields. In memory of Alf van der Poorten. Based on the proceedings of the international number theory conference, Newcastle, Australia, March 12–16, 2012. New York, NY: Springer (ISBN 978-1-4614-6641-3/hbk; 978-1-4614-6642-0/ebook). Springer Proceedings in Mathematics & Statistics 43, 99-128 (2013). Reviewer: Ilya D. Shkredov (Moskva) MSC: 11B30 11B13 11B75 94A60 PDFBibTeX XMLCite \textit{K. Bibak}, Springer Proc. Math. Stat. 43, 99--128 (2013; Zbl 1303.11022) Full Text: DOI arXiv
Brandner, Günther RSA, Dickson, LUC and Williams: a study on four polynomial-type public-key cryptosystems. (English) Zbl 1277.94015 Appl. Algebra Eng. Commun. Comput. 24, No. 1, 17-36 (2013). MSC: 94A60 11T71 PDFBibTeX XMLCite \textit{G. Brandner}, Appl. Algebra Eng. Commun. Comput. 24, No. 1, 17--36 (2013; Zbl 1277.94015) Full Text: DOI
Li, Angsheng; Pan, Yicheng Characterizations of locally testable linear- and affine-invariant families. (English) Zbl 1235.94066 Theor. Comput. Sci. 414, No. 1, 55-75 (2012). MSC: 94B25 11T71 68W30 PDFBibTeX XMLCite \textit{A. Li} and \textit{Y. Pan}, Theor. Comput. Sci. 414, No. 1, 55--75 (2012; Zbl 1235.94066) Full Text: DOI
Poulakis, Dimitrios Some lattice attacks on DSA and ECDSA. (English) Zbl 1266.94024 Appl. Algebra Eng. Commun. Comput. 22, No. 5-6, 347-358 (2011). Reviewer: Vladimír Lacko (Košice) MSC: 94A60 11T71 11Y16 94A62 PDFBibTeX XMLCite \textit{D. Poulakis}, Appl. Algebra Eng. Commun. Comput. 22, No. 5--6, 347--358 (2011; Zbl 1266.94024) Full Text: DOI
Andreeva, Elena; Stam, Martijn The symbiosis between collision and preimage resistance. (English) Zbl 1291.94047 Chen, Liqun (ed.), Cryptography and coding. 13th IMA international conference, IMACC 2011, Oxford, UK, December 12–15, 2011. Proceedings. Berlin: Springer (ISBN 978-3-642-25515-1/pbk). Lecture Notes in Computer Science 7089, 152-171 (2011). MSC: 94A60 11T71 68P30 PDFBibTeX XMLCite \textit{E. Andreeva} and \textit{M. Stam}, Lect. Notes Comput. Sci. 7089, 152--171 (2011; Zbl 1291.94047) Full Text: DOI
Guo, Hua; Li, Zhoujun; Mu, Yi; Zhang, Fan; Wu, Chuankun; Teng, Jikai An efficient dynamic authenticated key exchange protocol with selectable identities. (English) Zbl 1221.94075 Comput. Math. Appl. 61, No. 9, 2518-2527 (2011). MSC: 94A62 11T71 68P25 PDFBibTeX XMLCite \textit{H. Guo} et al., Comput. Math. Appl. 61, No. 9, 2518--2527 (2011; Zbl 1221.94075) Full Text: DOI
Håstad, Johan Satisfying degree-\(d\) equations over \(\mathrm{GF}[2]^{n}\). (English) Zbl 1343.68312 Goldberg, Leslie Ann (ed.) et al., Approximation, randomization, and combinatorial optimization. Algorithms and techniques. 14th international workshop, APPROX 2011, and 15th international workshop, RANDOM 2011, Princeton, NJ, USA, August 17–19, 2011. Proceedings. Berlin: Springer (ISBN 978-3-642-22934-3/pbk). Lecture Notes in Computer Science 6845, 242-253 (2011). MSC: 68W25 11T06 68Q17 68W20 PDFBibTeX XMLCite \textit{J. Håstad}, Lect. Notes Comput. Sci. 6845, 242--253 (2011; Zbl 1343.68312) Full Text: DOI
Koblitz, Ann Hibner; Koblitz, Neal; Menezes, Alfred Elliptic curve cryptography: the serpentine course of a paradigm shift. (English) Zbl 1213.94117 J. Number Theory 131, No. 5, 781-814 (2011). Reviewer: Dimitros Poulakis (Thessaloniki) MSC: 94A60 11T71 14G50 68P25 01A80 PDFBibTeX XMLCite \textit{A. H. Koblitz} et al., J. Number Theory 131, No. 5, 781--814 (2011; Zbl 1213.94117) Full Text: DOI
Shi, Hongsong; Jiang, Shaoquan; Qin, Zhiguang More efficient DDH pseudorandom generators. (English) Zbl 1201.94096 Des. Codes Cryptography 55, No. 1, 45-64 (2010). Reviewer: Guillermo Morales-Luna (Mexico) MSC: 94A60 11T71 PDFBibTeX XMLCite \textit{H. Shi} et al., Des. Codes Cryptography 55, No. 1, 45--64 (2010; Zbl 1201.94096) Full Text: DOI
May, Alexander Using LLL-reduction for solving RSA and factorization problems. (English) Zbl 1237.94078 Nguyen, Phong Q. (ed.) et al., The LLL algorithm. Survey and applications. Dordrecht: Springer (ISBN 978-3-642-02294-4/hbk; 978-3-642-02295-1/ebook). Information Security and Cryptography, 315-348 (2010). MSC: 94A60 68Q25 11Y16 PDFBibTeX XMLCite \textit{A. May}, in: The LLL algorithm. Survey and applications. Dordrecht: Springer. 315--348 (2010; Zbl 1237.94078) Full Text: DOI
Abe, Masayuki; Cui, Yang; Imai, Hideki; Kiltz, Eike Efficient hybrid encryption from ID-based encryption. (English) Zbl 1197.94171 Des. Codes Cryptography 54, No. 3, 205-240 (2010). Reviewer: Zlatko Varbanov (Veliko Tarnovo) MSC: 94A60 11T71 PDFBibTeX XMLCite \textit{M. Abe} et al., Des. Codes Cryptography 54, No. 3, 205--240 (2010; Zbl 1197.94171) Full Text: DOI
Ma, Changshe; Weng, Jian; Li, Yingjiu; Deng, Robert Efficient discrete logarithm based multi-signature scheme in the plain public key model. (English) Zbl 1215.94060 Des. Codes Cryptography 54, No. 2, 121-133 (2010). MSC: 94A60 11T71 PDFBibTeX XMLCite \textit{C. Ma} et al., Des. Codes Cryptography 54, No. 2, 121--133 (2010; Zbl 1215.94060) Full Text: DOI
Nojima, Ryo; Imai, Hideki; Kobara, Kazukuni; Morozov, Kirill Semantic security for the McEliece cryptosystem without random oracles. (English) Zbl 1196.94062 Des. Codes Cryptography 49, No. 1-3, 289-305 (2008). MSC: 94A60 11T71 14G50 PDFBibTeX XMLCite \textit{R. Nojima} et al., Des. Codes Cryptography 49, No. 1--3, 289--305 (2008; Zbl 1196.94062) Full Text: DOI
Koblitz, Neal; Menezes, Alfred Another look at non-standard discrete log and Diffie-Hellman problems. (English) Zbl 1156.94357 J. Math. Cryptol. 2, No. 4, 311-326 (2008). MSC: 94A60 68P25 11T71 PDFBibTeX XMLCite \textit{N. Koblitz} and \textit{A. Menezes}, J. Math. Cryptol. 2, No. 4, 311--326 (2008; Zbl 1156.94357) Full Text: DOI
Chen, Wenbin; Meng, Jiangtao Hardness of approximating the minimum solutions of linear Diophantine equations. (English) Zbl 1164.68007 Theor. Comput. Sci. 374, No. 1-3, 191-195 (2007). MSC: 68Q17 11D04 68W25 PDFBibTeX XMLCite \textit{W. Chen} and \textit{J. Meng}, Theor. Comput. Sci. 374, No. 1--3, 191--195 (2007; Zbl 1164.68007) Full Text: DOI
Joux, Antoine; Naccache, David; Thomé, Emmanuel When \(e\)-th roots become easier than factoring. (English) Zbl 1153.11345 Kurosawa, Kaoru (ed.), Advances in cryptology – ASIACRYPT 2007. 13th international conference on the theory and application of cryptology and information security, Kuching, Malaysia, December 2-6, 2007. Proceedings. Berlin: Springer (ISBN 978-3-540-76899-9/pbk). Lecture Notes in Computer Science 4833, 13-28 (2007). MSC: 11Y16 11T71 11Y05 94A60 PDFBibTeX XMLCite \textit{A. Joux} et al., Lect. Notes Comput. Sci. 4833, 13--28 (2007; Zbl 1153.11345) Full Text: DOI
Shao, Zuhua A provably secure short signature scheme based on discrete logarithms. (English) Zbl 1134.94010 Inf. Sci. 177, No. 23, 5432-5440 (2007). Reviewer: Juan Tena Ayuso (Valladolid) MSC: 94A62 94A60 11T71 68P25 PDFBibTeX XMLCite \textit{Z. Shao}, Inf. Sci. 177, No. 23, 5432--5440 (2007; Zbl 1134.94010) Full Text: DOI
Canard, Sébastien; Schoenmakers, Berry; Stam, Martijn; Traoré, Jacques List signature schemes. (English) Zbl 1091.94028 Discrete Appl. Math. 154, No. 2, 189-201 (2006). MSC: 94A62 11A07 PDFBibTeX XMLCite \textit{S. Canard} et al., Discrete Appl. Math. 154, No. 2, 189--201 (2006; Zbl 1091.94028) Full Text: DOI
Chen, Lin; Huang, Xiaoqin; You, Jinyuan Group signature schemes with forward secure properties. (English) Zbl 1083.94530 Appl. Math. Comput. 170, No. 2, 841-849 (2005). MSC: 94A62 94A60 11A07 11T71 PDFBibTeX XMLCite \textit{L. Chen} et al., Appl. Math. Comput. 170, No. 2, 841--849 (2005; Zbl 1083.94530) Full Text: DOI
Tsaban, Boaz Bernoulli numbers and the probability of a birthday surprise. (English) Zbl 1022.60006 Discrete Appl. Math. 127, No. 3, 657-663 (2003). Reviewer: Nicko G.Gamkrelidze (Moskva) MSC: 60C05 11B68 PDFBibTeX XMLCite \textit{B. Tsaban}, Discrete Appl. Math. 127, No. 3, 657--663 (2003; Zbl 1022.60006) Full Text: DOI arXiv
ElGamal, Taher A public key cryptosystem and a signature scheme based on discrete logarithms. (English) Zbl 0571.94014 IEEE Trans. Inf. Theory 31, 469-472 (1985). MSC: 94A60 94A62 11Y16 11T71 68P25 PDFBibTeX XMLCite \textit{T. ElGamal}, IEEE Trans. Inf. Theory 31, 469--472 (1985; Zbl 0571.94014) Full Text: DOI