From: Neil Smith Date: Tue, 15 Jul 2014 09:58:37 +0000 (+0100) Subject: Copied over updated slide layout from presentation-slides X-Git-Url: https://git.njae.me.uk/?a=commitdiff_plain;h=b2bff955d11597f85c5e1935165a44fb0e5e487e;p=cipher-training.git Copied over updated slide layout from presentation-slides --- diff --git a/slides/affine-break.html b/slides/affine-break.html index ddd8170..8a07978 100644 --- a/slides/affine-break.html +++ b/slides/affine-break.html @@ -36,6 +36,11 @@ color: #ff6666; text-shadow: 0 0 20px #333; padding: 2px 5px; + } + .indexlink { + position: absolute; + bottom: 1em; + left: 1em; } .float-right { float: right; @@ -53,6 +58,12 @@ b | e | h | k | n | q | t | w | z | c | f | i | l | o | r | u | x | a | d | g | --- +layout: true + +.indexlink[[Index](index.html)] + +--- + # Duplicate and extend your `caesar_break()` function * How to cycle through all the keys? diff --git a/slides/affine-encipher.html b/slides/affine-encipher.html index 30f3900..c0f30cb 100644 --- a/slides/affine-encipher.html +++ b/slides/affine-encipher.html @@ -36,6 +36,11 @@ color: #ff6666; text-shadow: 0 0 20px #333; padding: 2px 5px; + } + .indexlink { + position: absolute; + bottom: 1em; + left: 1em; } .float-right { float: right; @@ -56,9 +61,16 @@ An extension of Caesar ciphers * Count the gaps in the letters. --- + +layout: true + +.indexlink[[Index](index.html)] + +--- + # How affine ciphers work -_ciphertext_letter_ =_plaintext_letter_ Ã a + b +.ciphertext[_ciphertext_letter_] =.plaintext[_plaintext_letter_] Ã a + b * Convert letters to numbers * Take the total modulus 26 @@ -83,11 +95,11 @@ This is not always defined in modular arithmetic. For instance, 7 Ã 4 = 28 = 2 Result from number theory: only numbers coprime with _n_ have multiplicative inverses in arithmetic mod _n_. -Another result from number theory: for non-negative integers _a_ and _n_, and there exist unique integers _x_ and _y_ such that _ax_ + _ny_ = gcd(_a_, _b_) +Another result from number theory: for non-negative integers _m_ and _n_, and there exist unique integers _x_ and _y_ such that _mx_ + _ny_ = gcd(_m_, _n_) Coprime numbers have gcd of 1. -_ax_ + _ny_ = 1 mod _n_. But _ny_ mod _n_ = 0, so _ax_ = 1 mod _n_, so _a_ = _x_^-1. +_mx_ + _ny_ = 1 mod _n_. But _ny_ mod _n_ = 0, so _mx_ = 1 mod _m_, so _m_ = _x_^-1. Perhaps the algorithm for finding gcds could be useful? diff --git a/slides/aims.html b/slides/aims.html index fcf0c70..1d1da36 100644 --- a/slides/aims.html +++ b/slides/aims.html @@ -37,18 +37,29 @@ text-shadow: 0 0 20px #333; padding: 2px 5px; } + .indexlink { + position: absolute; + bottom: 1em; + left: 1em; + }

+layout: true
+
+.indexlink[[Index](index.html)]
+
+---
+
 # Aims
 
 Material aimed for two (three?) audiences
 
 1. Teacher CPD
 2. In-school resources for children
-3. (Outreach resources, mainly Bletchley Park)
+3. Outreach resources, mainly Bletchley Park
 
 After your suggestions on how to extend these notes to hit these audiences
 
diff --git a/slides/alternative-plaintext-scoring.html b/slides/alternative-plaintext-scoring.html
index d6f4aa1..1b2b882 100644
--- a/slides/alternative-plaintext-scoring.html
+++ b/slides/alternative-plaintext-scoring.html
@@ -36,6 +36,11 @@
         color: #ff6666;
         text-shadow: 0 0 20px #333;
         padding: 2px 5px;
+      }
+      .indexlink {
+        position: absolute;
+        bottom: 1em;
+        left: 1em;
       }
        .float-right {
         float: right;
@@ -49,6 +54,12 @@
 
 ---
 
+layout: true
+
+.indexlink[[Index](index.html)]
+
+---
+
 # Back to frequency of letter counts
 
 Letter | Count
diff --git a/slides/caesar-break.html b/slides/caesar-break.html
index 5ea77b9..4d2ebfa 100644
--- a/slides/caesar-break.html
+++ b/slides/caesar-break.html
@@ -36,6 +36,11 @@
         color: #ff6666;
         text-shadow: 0 0 20px #333;
         padding: 2px 5px;
+      }
+      .indexlink {
+        position: absolute;
+        bottom: 1em;
+        left: 1em;
       }
        .float-right {
         float: right;
@@ -51,6 +56,12 @@
 
 ---
 
+layout: true
+
+.indexlink[[Index](index.html)]
+
+---
+
 # Human vs Machine
 
 Slow but clever vs Dumb but fast
@@ -93,6 +104,8 @@ What does English look like?
 
 How do we define "closeness"?
 
+## Here begineth the yak shaving
+
 ---
 
 # What does English look like?
@@ -154,6 +167,7 @@ open()
 * Count them
 ```python
 import collections
+collections.Counter()
 ```
 
 Create the `language_models.py` file for this.
@@ -279,7 +293,7 @@ Use `logger.debug()`, `logger.info()`, etc. to log a message.
 
 ---
 
-# How much ciphertext do we need?
+# Homework: how much ciphertext do we need?
 
 ## Let's do an experiment to find out
 
@@ -289,6 +303,18 @@ Use `logger.debug()`, `logger.info()`, etc. to log a message.
 4. Score 1 point if `caesar_cipher_break()` recovers the correct key
 5. Repeat many times and with many plaintext lengths
 
+```python
+import csv
+
+def show_results():
+    with open('caesar_break_parameter_trials.csv', 'w') as f:
+        writer = csv.DictWriter(f, ['name'] + message_lengths, 
+            quoting=csv.QUOTE_NONNUMERIC)
+        writer.writeheader()
+        for scoring in sorted(scores.keys()):
+            scores[scoring]['name'] = scoring
+            writer.writerow(scores[scoring])
+```