Enhancements to private and public keys articles

docs/cryptography/asymmetric/ed25519.md

@@ -1,26 +1,11 @@
 # Ed25519 curve
 
 !!! danger
-    Article author is nowhere close to being a cryptographer. Be sceptical on accuracy.
+    Author is nowhere close to being a cryptographer. Be sceptical on accuracy.
 
 !!! note
     This article is only about the underlying curve. Public key derivation and signing algorithm will be treated separately. 
 
-!!! note
-    Before we get to Monero, a little bit of context. We are talking asymmetric cryptography here.
-    The "asymmetric" simply means the are two keys:
-    
-    * the private key (used primarily for signing data and for decrypting data)
-    * the public key (used primarily for signature verification and encrypting data)
-    
-    This is in contrast to symmetric cryptography which uses a single (secret) key.
-    
-    Historically, asymmetric cryptography was based on the problem of factorization of a very large integers
-    back into prime numbers (which is practically impossible for large enough integers).
-    
-    Recently, asymmetric cryptography is based on a mathematical notion of elliptic curves.
-    Ed25519 is a specific, well researched and standardized elliptic curve.      
-
 Monero employs Ed25519 elliptic curve as a basis for its key pair generation.
  
 However, Monero does not exactly follow EdDSA reference signature scheme.

docs/cryptography/asymmetric/intro.md

@@ -1,7 +1,7 @@
 # Asymmetric cryptography used in Monero
 
 !!! danger
-    Article author is nowhere close to being a cryptographer. Be sceptical on accuracy.
+    Author is nowhere close to being a cryptographer. Be sceptical on accuracy.
 
 Before we get to Monero specific stuff, a little bit of context. We are talking asymmetric cryptography here.
 The "asymmetric" simply means the are two keys:

docs/cryptography/asymmetric/private-key.md

@@ -1,12 +1,9 @@
 # Private keys in Monero
 
 !!! danger
-    Article author is nowhere close to being a cryptographer. Be sceptical on accuracy.
+    Author is nowhere close to being a cryptographer. Be sceptical on accuracy.
 
-!!! warning
+In Monero, the root private key is generated [randomly](/cryptography/prng). Other private keys are derived deterministically from the root private key.
-    Article is a work in progress.
-
-Private key is generated [randomly](/cryptography/prng).
 
 Private key must be kept secret.
 
@@ -24,10 +21,31 @@ In user-facing contexts, private key is encoded in a [little-endian](https://en.
 
 ## Relation to Ed25519
 
-Being a simple random integer, private key is not specific to any particular asymmetric cryptography scheme.
+Being simply a random integer, private key is not specific to any particular asymmetric cryptography scheme.
 
-However, before deriving Ed25519 public key, the private key is subject to modulo `l`,
+In context of Monero EC cryptography the private key is a number the base point `G` is multiplied by.
-where `l` is the maximum scalar allowed by [Ed25519 scheme](/cryptography/asymmetric/ed25519).
+The result of the multiplication is the public key `P` (another point on the curve).
+Multiplication of a point by a number has a very special definition in EC cryptography.
+See this [this guide](https://blog.cloudflare.com/a-relatively-easy-to-understand-primer-on-elliptic-curve-cryptography/) for details.
+
+### Key strength
+
+Before deriving Ed25519 public key, the private key is subject to modulo `l`,
+where `l` is the maximum scalar allowed by the [Ed25519 scheme](/cryptography/asymmetric/ed25519).
 
 The `l` is on the order of 2^252, so the effective key strength is technically 252 bits, not 256 bits.
-This is standard for EC cryptography and is more of a cosmetic nuance than any real concern.
+This is standard for EC cryptography and is more of a cosmetic nuance than any concern.
+
+## Private spend key
+
+Private spend key is used to spend moneros.
+ 
+More specifically, it is used to build one-time private keys which allow to spend related outputs.
+
+## Private view key
+
+Private view key is used to recognize your incoming transactions on the otherwise opaque blockchain.
+
+## One-time private keys
+
+One-time private key like construct is used in [stealth addresses](https://monero.stackexchange.com/questions/1409/constructing-a-stealth-monero-address).

docs/cryptography/asymmetric/public-key.md

@@ -1,7 +1,7 @@
 # Public keys in Monero
 
 !!! danger
-    Article author is nowhere close to being a cryptographer. Be sceptical on accuracy.
+    Author is nowhere close to being a cryptographer. Be sceptical on accuracy.
 
 !!! warning
     Article is a work in progress.
@@ -36,3 +36,8 @@ However, the addition is **not** a simple vector addition. It has a very specifi
 definition nicely described in [this article](https://blog.cloudflare.com/a-relatively-easy-to-understand-primer-on-elliptic-curve-cryptography/).
 What is important is that result of addition is always a point on the curve.
 For example, G + G is another point on the curve.
+
+## Use cases
+
+[Monero address](/public-address/standard-address) is composed of public spend key and public view key.
+These keys are used to build stealth addresses to receive payments.  

docs/index.md

@@ -1,4 +1,4 @@
-# Unofficial Monero Documentation (1% done)
+# Unofficial Monero Documentation (2% done)
 
 Monerodocs attempts to organize basic technical knowledge on Monero in one place.
 

docs/public-address/standard-address.md

@@ -37,6 +37,11 @@ It totals to 69 bytes. The bytes are then encoded ([src](https://github.com/mone
 
 `4AdUndXHHZ6cfufTMvppY6JwXNouMBzSkbLYfpAV5Usx3skxNgYeYTRj5UzqtReoS44qo9mtmXCqY45DJ852K5Jv2684Rge`
 
+## Generating
+
+Standard address is derived from the root private key. TODO: describe.
+
 ## Reference
 
+* [StackExchenge answer](https://monero.stackexchange.com/questions/980/what-are-the-public-viewkeys-and-spendkeys)
 * [https://xmr.llcoins.net/addresstests.html](https://xmr.llcoins.net/addresstests.html)

docs/public-address/subaddress.md

@@ -33,6 +33,10 @@ All subaddresses can be derived from the wallet seed.
 
 Additionally, you conveniently manage your subaddresses within a single user interface.
 
+## Wallet level feature
+
+Subaddresses are a wallet-level feature to construct and interpret transactions. They do not affect the consensus. 
+
 ## Data structure
 
 Subaddress has a dedicated "network byte":
@@ -46,6 +50,20 @@ Otherwise the data structure is the same as for [standard address](/public-addre
 Each subaddress conceptually has an index (with 0 being the base standard address).
 The index is not directly included in subaddress structure but is used as input to create the private spend key.
 
+## Generating
+
+The private key `m` related to a subaddress is derived as follows:
+    
+    m = Hs(a || i)
+    
+Where:
+
+* `Hs` is a Keccak-256 hash function interpreted as integer and modulo `l` (maximum Ed25519 scalar)
+* `a` is a private view key
+* `i` is a subaddress index
+
+TODO: describe rest of the procedure.
+
 ## Caveates
 
 * Subaddress **cannot** be used to receive transactions having multiple destinations (e.g. pool payouts). Only the standard address (the one with index == 0) can receive such transactions.