
Motivated by the BSD conjecture, Mestre
(Mestre, 1982) and Nagao (Nagao, 1992), followed
by subsequent researchers Elkies and Koblitz (Elkies
and Klagsbrun, 2020), and Bobba (Bober, 2013), in-
troduced certain sums (see (Kazalicki and Vlah, 2023,
Section 2) for a list of Mestre-Nagao sums) that are
heuristically expected to detect curves of high ana-
lytic rank. One such example is the following
S
0
(t) =
1
logt
∑
q<t
good reduction
a
q
(E) ·log q
q
.
Given the above, it is of clear scientific interest to
study the cardinality of E(F
q
) as the curve’s coeffi-
cients
3
A and B are fixed and the prime varies.
Motivation. An AI-based method aiming at en-
hancing Schoof’s algorithm for finding the number of
points of an elliptic curve is proposed in (Maimut¸ and
Matei, 2022). The authors focus on elliptic curves
of prime order. The obtained results can be of gen-
eral interest in terms of ECC algorithms and may also
be combined with already established algorithmic im-
provements to obtain better software implementation
timings.
Our method is based on the one presented in
(Maimut¸ and Matei, 2022), while the main difference
between the two methods is given by the way we con-
structed our datasets. In (Maimut¸ and Matei, 2022),
the dataset is composed of various triplets of the form
(p,A,B). In other words, both the prime p and the el-
liptic curve E(A,B) vary, whereas in the present work
we consider two separate situations. Firstly, we fix an
elliptic curve and then we study the behaviour of the
normalized Frobenius trace
e
δ of E(A,B) as the prime
p varies. Secondly, we fix the prime p and we ana-
lyze the value of
e
δ when the pair (A,B) takes various
values.
We choose this approach because, from a theo-
retical point of view, it should produce better results
than the more general setting found in (Maimut¸ and
Matei, 2022). Also, we further divide the curves con-
sidered in two classes, namely the CM curves and
non-CM curves, as the distribution of the values of
|E(A,B| varies greatly for each class. The main ob-
jective of this paper is to improve the results found in
(Maimut¸ and Matei, 2022) by considering particular
cases. The use of Machine Learning (ML) models is
motivated by the connection between Hasse’s bound
for
e
δ and the range of the activation functions used for
ML models.
3
E(F
q
) : y
2
= x
3
+ Ax + B
Further Motivation. For the negative results we
present in some of our experiments, we provide the
reader with a twofold explanation.
1. Impossibility results, as well as unsuccessful di-
rections are often underestimated or rarely re-
ported in the literature (Howitt and Wilson, 2014;
Truran, 2013), leading to the risk of repeated er-
rors. We strongly believe that by sharing our out-
comes we can contribute to a collective learning
process. Our approach is in accordance with the
recommendation in (Tao, b) to document mistakes
in order to prevent their recurrence in the future.
2. In the majority of scientific reports and papers,
authors often depict their results as if they were
achieved in a straightforward manner. This
paradigm contributes to a distorted perception of
research (Medawar, 1963; Howitt and Wilson,
2014; Tao, a; Weidman, 1965), promoting the
misconception that failure and unexpected out-
comes might not be considered natural directions
of scientific attempts (Howitt and Wilson, 2014;
Schwartz, 2008). On the practical side, we aim
at providing readers with meaningful insights into
the design phase of elliptic curve-based crypto-
graphic primitives or protocols.
Related Work. A machine learning (ML) classifier
was used in (He et al., 2023) to predict the rank and
torsion order of an elliptic curve or a genus 2 curve.
In the case of elliptic curves over Q, rank 0 curves
were distinguished from those with rank 1 by logis-
tic regression with accuracy > 97%. Based on their
torsion order, E(Q) with order 1 where distinguished
from ones with order 2 with precision 99.9%. For
other classifications we refer the reader to (He et al.,
2023).
In (He et al., 2022a), the authors develop a ML
model that distinguishes between complex multiplica-
tion (CM) elliptic curves and non-CM elliptic curves
with a reported accuracy of 100%. This model takes
as input vectors containing the values of the Frobe-
nius trace δ for primes p up to 10000. This task is not
considered hard, since for a CM curve the probability
that δ = 0 is 50%, whereas for a non-CM curve it is
negligible.
The authors of (Alessandretti et al., 2023) con-
sider using ML models for predicting certain quan-
tities that appear in the BSD conjecture (Birch and
Swinnerton-Dyer, 1965), represented by the problem
of finding the number of points that have coordinates
in Q. When considering only the Weierstrass coeffi-
cients as input, the authors obtained unsatisfactory re-
sults. They also compare this task with the failure of
predicting prime numbers using ML. However, when
ICISSP 2025 - 11th International Conference on Information Systems Security and Privacy
438