Shorten; don't repeat in the README.md file what's available online

README.md

@@ -7,8 +7,8 @@ Minisign is a dead simple tool to sign files and verify signatures.
 For more information, please refer to the
 [Minisign documentation](https://jedisct1.github.io/minisign/)
 
-Tarballs and pre-compiled binaries for Windows and OSX can be verified with
-the following public key:
+Tarballs and pre-compiled binaries can be verified with the following
+public key:
 
     RWQf6LRCGA9i53mlYecO4IzT51TGPpvWucNSCh1CBM0QTaLn73Y7GFO3
 
@@ -27,125 +27,3 @@ Compilation:
     $ make
     # make install
 
-Creating a key pair
--------------------
-
-    $ minisign -G
-
-The public key is printed and put into the `minisign.pub` file. The secret key
-is encrypted and saved as `minisign.key` file.
-
-Signing a file
---------------
-
-    $ minisign -Sm myfile.txt
-
-Or to include a comment in the signature, that will be verified and
-displayed when verifying the file:
-
-    $ minisign -Sm myfile.txt -t 'This comment will be signed as well'
-
-The signature is put into `myfile.txt.minisig`.
-
-Verifying a file
-----------------
-
-    $ minisign -Vm myfile.txt -P RWQf6LRCGA9i53mlYecO4IzT51TGPpvWucNSCh1CBM0QTaLn73Y7GFO3
-
-or
-
-    $ minisign -Vm myfile.txt -p signature.pub
-
-This requires the signature `myfile.txt.minisig` to be present in the same
-directory.
-
-The public key can either reside in a file (`./minisign.pub` by default) or be
-directly specified on the command line.
-
-Usage
------
-
-    $ minisign -G [-p pubkey] [-s seckey]
-    $ minisign -S [-x sigfile] [-s seckey] [-c untrusted_comment] [-t trusted_comment] -m file
-    $ minisign -V [-x sigfile] [-p pubkeyfile | -P pubkey] [-q] -m file
-
-    -G                generate a new key pair
-    -S                sign a file
-    -V                verify that a signature is valid for a given file
-    -m <file>         file to sign/verify
-    -p <pubkeyfile>   public key file (default: ./minisign.pub)
-    -P <pubkey>       public key, as a base64 string
-    -s <seckey>       secret key file (default: ./minisign.key)
-    -x <sigfile>      signature file (default: <file>.minisig)
-    -c <comment>      add a one-line untrusted comment
-    -t <comment>      add a one-line trusted comment
-    -q                quiet mode, suppress output
-    -v                display version number
-
-Trusted comments
-----------------
-
-Signature files include an untrusted comment line that can be freely
-modified, even after signature creation.
-
-They also include a second comment line, that cannot be modified
-without the secret key.
-
-Trusted comments can be used to add instructions or application-specific
-metadata (intended file name, timestamps, resource identifiers,
-version numbers to prevent downgrade attacks).
-
-Compatibility with OpenBSD signify
-----------------------------------
-
-Signature written by minisign can be verified using OpenBSD's signify
-tool: public key files and signature files are compatible.
-
-However, minisign uses a slightly different format to store secret keys.
-
-Minisign signatures include trusted comments in addition to untrusted
-comments. Trusted comments are signed, thus verified, before being
-displayed.
-
-This adds two lines to the signature files, that signify silently ignores.
-
-Signature format
-----------------
-
-    untrusted comment: <arbitrary text>
-    base64(<signature_algorithm> || <key_id> || <signature>)
-    trusted_comment: <arbitrary text>
-    base64(<global_signature>)
-
-* `signature_algorithm`: `Ed`
-* `key_id`: 8 random bytes, matching the public key
-* `signature`: `ed25519(<file data>)`
-* `global_signature`: `ed25519(<signature> || <trusted_comment>)`
-
-Public key format
------------------
-
-    untrusted comment: <arbitrary text>
-    base64(<signature_algorithm> || <key_id> || <public_key>)
-
-* `signature_algorithm`: `Ed`
-* `key_id`: 8 random bytes
-* `public_key`: Ed25519 public key
-
-Secret key format
------------------
-
-    untrusted comment: <arbitrary text>
-    base64(<signature_algorithm> || <kdf_algorithm> || <cksum_algorithm> ||
-           <kdf_salt> || <kdf_opslimit> || <kdf_memlimit> || <keynum_sk>)
-
-* `signature_algorithm`: `Ed`
-* `kdf_algorithm`: `Sc`
-* `cksum_algorithm`: `B2`
-* `kdf_salt`: 32 random bytes
-* `kdf_opslimit`: `crypto_pwhash_scryptsalsa208sha256_OPSLIMIT_SENSITIVE`
-* `kdf_memlimit`: `crypto_pwhash_scryptsalsa208sha256_MEMLIMIT_SENSITIVE`
-* `keynum_sk`: `<kdf_output> ^ (<key_id> || secret_key> || <checksum>)`
-* `key_id`: 8 random bytes
-* `secret_key`: Ed25519 secret key
-* `checksum`: `Blake2b(<signature_algorithm> || <key_id> || <secret_key>)`, 32 bytes