fundamentals about hashes: various grammar/spelling fixes (#663)

appendix-bitcoin-fundamentals-review.asciidoc

@@ -79,7 +79,7 @@ While it takes longer than a single sentence, the SHA256 function processes the
 
 Now at this point you might be wondering how it is possible for a function that digests data of unlimited size to produce a unique fingerprint that is a fixed-size number?
 
-In theory, since there an infinite number of possible pre-images (inputs) and only a finite number of fingerprints, there must be many pre-images that produce the same 256-bit fingerprint. when two pre-images produce the same hash, this is known as a _collision_.
+In theory, since there is an infinite number of possible pre-images (inputs) and only a finite number of fingerprints, there must be many pre-images that produce the same 256-bit fingerprint. When two pre-images produce the same hash, this is known as a _collision_.
 
 In practice, a 256-bit number is so large that you will never find a collision on purpose. Cryptographic hash functions work on the basis that a search for a collision is a brute-force effort that takes so much energy and time that it is not practically possible.
 
@@ -89,17 +89,17 @@ Deterministic:: The same input always produces the same hash.
 
 Irreversible:: It is not possible to compute the pre-image of a hash.
 
-Collission-Proof:: It is computationally infeasible to find two messages that have the same hash.
+Collision-Proof:: It is computationally infeasible to find two messages that have the same hash.
 
 Uncorrelated:: A small change in the input produces such a big change in the output that the output seems uncorrelated to the input.
 
 Uniform/Random:: A cryptographic hash function produces hashes that are uniformly distributed across the entire 256-bit space of possible outputs. The output of a hash appears to be random, though it is not truly random.
 
-Using these features of cryptographic hashes, we can do build some interesting applications:
+Using these features of cryptographic hashes, we can build some interesting applications:
 
 Fingerprints:: A hash can be used to fingerprint a file or message so that it can be uniquely identified. Hashes can be used as universal identifiers of any data set.
 
-Integrity Proof:: A fingerprint of a file or message demonstrates its integrity, as the file or message cannot be tampered with or modified in any way without changing the fingerprint. This is often use to ensure software has not been tampered with before installing it on your computer.
+Integrity Proof:: A fingerprint of a file or message demonstrates its integrity, as the file or message cannot be tampered with or modified in any way without changing the fingerprint. This is often used to ensure software has not been tampered with before installing it on your computer.
 
 Commitment/Non-repudiation:: You can commit to a specific pre-image (e.g. a number or message) without revealing it, by publishing its hash. Later, you can reveal the secret and everyone can verify that it is the same thing you committed to earlier because it produces the published hash.
 

preface.asciidoc

@@ -198,6 +198,7 @@ Following is an alphabetically sorted list of all the GitHub contributors, inclu
 * Paul Wackerow (@wackerow)
 * René Köhnke (@rene78)
 * Ricardo Marques (@RicardoM17)
+* Sebastian Falbesoner (@theStack)
 * Sergei Tikhomirov (@s-tikhomirov)
 * Simone Bovi (@SimoneBovi)
 * Taylor Masterson (@tjmasterson)