-
Notifications
You must be signed in to change notification settings - Fork 1
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
- Loading branch information
Tatiana Bradley
committed
Nov 5, 2014
1 parent
db9be7d
commit 1bd56e2
Showing
5 changed files
with
102 additions
and
1 deletion.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,29 @@ | ||
\chapter{Elliptic Curve Basics}% | ||
\label{sec:elliptic-curves} | ||
|
||
% Weierstrass equation | ||
\begin{defn} | ||
Let $K$ be a field. An $\textbf{elliptic curve $E$ over $K$}$ is defined by an equation: | ||
$$E : y^2 + a_1xy + a_3y = x^3 + a_2x^2 + a_4x + a_6$$ | ||
where $a_1, a_2, a_3, a_4, a_6 \in K$ and the $\textbf{discriminant}$ $\Delta$ is non-zero. This equation is called a $\textbf{Weierstrass equation}$. | ||
\end{defn} | ||
|
||
% L-rational points | ||
\begin{defn} | ||
With $K$ and $E$ defined as above, the set of $\textbf{L-rational points}$ on $E$ for any extension $L$ of $K$ is the set of pairs $(x, y) \in L \times L$ that | ||
satisfy $E$, together with $\OO$, the point at infinity. | ||
|
||
The set of L-rational points is denoted $E(L)$. | ||
\end{defn} | ||
|
||
% Trace of Frobenius | ||
\begin{defn} | ||
Let $E$ be an elliptic curve over a finite field $\finfield$. The $\textbf{trace of Frobenius}$ t is defined by: | ||
$$ \#E(\finfield) = q + 1 - t, $$ | ||
where $\#E(\finfield)$ is the number of elements in $E(\finfield)$. | ||
\end{defn} | ||
|
||
\begin{rmk} | ||
The trace of Frobenius is equal to one if and only if $E(\finfield)$ has exactly $q$ elements. This has important implications | ||
for cryptography, as we will see. | ||
\end{rmk} |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,12 @@ | ||
\chapter{Formal Power Series and Formal Logarithm}% | ||
\label{sec:formal-log} | ||
|
||
\section{Formal Power Series} | ||
|
||
%% Defintion of | ||
\begin{defn} | ||
\end{defn} | ||
|
||
|
||
\section{Formal Logarithm} | ||
Hello |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,35 @@ | ||
\chapter{P-adic numbers}% | ||
\label{sec:p-adics} | ||
|
||
\section{The p-adics} | ||
|
||
\begin{defn} | ||
For a rational number $a$ and a prime number $p$, separate out all factors of $p$ from $a$ and write: $$ a = p^r \dfrac{m}{n} $$ where $r$, $m$ and $n$ are integers, and $p$ does not divide $m$ or $n$. The exponent $r$ is called the $\textbf{p-adic ordinal}$ of $a$, denoted $\text{ord}_p(a)$. | ||
\end{defn} | ||
|
||
% The absolute value | ||
\begin{defn} | ||
For a prime $p$, we define a function $|.|_p : \Q \to \Q_{\ge 0}$ where for $a \in \Q$: | ||
$$ | ||
|a|_p = \left\{ | ||
\begin{array}{ll} | ||
p^{-\text{ord}_p(a)} & \quad a \neq 0 \\ | ||
0 & \quad a = 0. | ||
\end{array} | ||
\right. | ||
$$ | ||
The function $|.|_p$ is called the $\textbf{p-adic absolute value}$. | ||
\end{defn} | ||
|
||
\begin{prop} | ||
The p-adic absolute value is a norm on $\Q$, and induces a metric $$d_p(a, \ b) = | a - b |_p$$ for $a, b \in \Q$. | ||
\end{prop} | ||
|
||
\begin{defn} | ||
A p-adic number $a$ is called a $\textbf{p-adic integer}$ if $ord_p(a) \ge 0$. The set of all p-adic integers is | ||
denoted $\Z_p$. | ||
\end{defn} | ||
|
||
\begin{rmk} | ||
A p-adic integer is always of the form $$a_0 + a_1p + a_2p^2 + ... ,$$ i.e., all powers of $p$ are non-negative. | ||
\end{rmk} |
Binary file not shown.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters