reorganizes steps inner to content::encrypt to improve performance

Cargo.toml

@@ -5,7 +5,7 @@
 
 [package]
 authors = ["sean watters <sean@watters.io>"]
-description = "\"Reasonably Good Privacy\""
+description = "Relatively Good Privacy"
 categories = ["cryptography"]
 edition = "2021"
 homepage = "https://github.com/seanwatters/RGP"
@@ -14,7 +14,7 @@ license = "MIT"
 name = "rgp"
 readme = "README.md"
 repository = "https://github.com/seanwatters/RGP"
-version = "0.1.6"
+version = "0.1.7"
 
 [dependencies]
 chacha20 = "0.9.1"

README.md

@@ -6,7 +6,7 @@
 [![docs.rs](https://docs.rs/rgp/badge.svg)](https://docs.rs/rgp/)
 [![dependency status](https://deps.rs/repo/github/seanwatters/RGP/status.svg)](https://deps.rs/repo/github/seanwatters/RGP)
 
-"Reasonably Good Privacy"
+Relatively Good Privacy 
 
 ## Usage
 
@@ -85,24 +85,24 @@ For the 8mb example with 20,000 recipients, on my M1 MacBook Pro
 
 | Operation               | Time      |
 | ----------------------- | --------- |
-| encrypt (multi-thread)  | 101.76 ms |
-| encrypt (single-thread) | 766.31 ms |
+| encrypt (multi-thread)  | 97.186 ms |
+| encrypt (single-thread) | 764.00 ms |
 | extract                 | 486.00 µs |
 | decrypt                 | 44.729 ms |
 
 Doing the equivalent operation for just 1 recipient on 8mb is
 
 | Operation               | Time      |
 | ----------------------- | --------- |
-| encrypt (multi-thread)  | 61.537 ms |
-| encrypt (single-thread) | 63.758 ms |
+| encrypt (multi-thread)  | 61.212 ms |
+| encrypt (single-thread) | 61.314 ms |
 | decrypt                 | 44.729 ms |
 
 When benchmarked in isolation, the signing operation (internal to the `encrypt` function) and verifying operation (internal to the `decrypt` function), take 28.469 ms and 14.209 ms, respectively.
 
 To check performance on your machine, run `cargo bench` (or `cargo bench --no-default-features` to disable multi-threading). You can also view the latest benches in the GitHub CI [workflow](https://github.com//seanwatters/RGP/actions/workflows/ci.yml) under job/Benchmark or job/Benchmark (single threaded).
 
-**NOTE:** the content signing/encryption logic is done in a separate thread from the per-recipient **content key** encryption, and the **content key** encryption work is done in a Rayon `par_chunks_mut` loop, so the number of threads does have an impact on performance.
+**NOTE:** in multi-threaded mode the content signing/encryption logic is done in a separate thread from the per-recipient **content key** encryption, and the **content key** encryption work is done in a Rayon `par_chunks_mut` for loop. There is likely an opportunity for further parallelization in the content encryption and signing step.
 
 ## Encrypted Format
 

src/lib.rs

@@ -128,6 +128,33 @@ pub mod content {
         let nonce = ChaChaAEAD::generate_nonce(&mut rand_core::OsRng);
         let content_key = ChaChaAEAD::generate_key(&mut rand_core::OsRng);
 
+        // sign/encrypt content
+
+        #[cfg(feature = "multi-thread")]
+        let sign_and_encrypt_handle = thread::spawn(move || {
+            let signature = super::signature::sign(&fingerprint, &content);
+            content.extend(signature);
+
+            let content_cipher = ChaChaAEAD::new(&content_key);
+            match content_cipher.encrypt(&nonce, content.as_ref()) {
+                Ok(encrypted_content) => Ok(encrypted_content),
+                Err(_) => Err("failed to encrypt content"),
+            }
+        });
+
+        #[cfg(not(feature = "multi-thread"))]
+        let encrypted_content = {
+            let signature = super::signature::sign(&fingerprint, &content);
+            content.extend(signature);
+
+            let content_cipher = ChaChaAEAD::new(&content_key);
+            match content_cipher.encrypt(&nonce, content.as_ref()) {
+                Ok(encrypted_content) => encrypted_content,
+                Err(_) => return Err("failed to encrypt content"),
+            }
+        };
+
+        // generate components
         let e_priv_key = StaticSecret::random_from_rng(rand_core::OsRng);
         let ot_pub_key = PublicKey::from(&e_priv_key);
 
@@ -157,32 +184,6 @@ pub mod content {
 
         out.extend(&keys_header);
 
-        // sign/encrypt content
-
-        #[cfg(feature = "multi-thread")]
-        let sign_and_encrypt_handle = thread::spawn(move || {
-            let signature = super::signature::sign(&fingerprint, &content);
-            content.extend(signature);
-
-            let content_cipher = ChaChaAEAD::new(&content_key);
-            match content_cipher.encrypt(&nonce, content.as_ref()) {
-                Ok(encrypted_content) => Ok(encrypted_content),
-                Err(_) => Err("failed to encrypt content"),
-            }
-        });
-
-        #[cfg(not(feature = "multi-thread"))]
-        let encrypted_content = {
-            let signature = super::signature::sign(&fingerprint, &content);
-            content.extend(signature);
-
-            let content_cipher = ChaChaAEAD::new(&content_key);
-            match content_cipher.encrypt(&nonce, content.as_ref()) {
-                Ok(encrypted_content) => encrypted_content,
-                Err(_) => return Err("failed to encrypt content"),
-            }
-        };
-
         let mut encrypted_keys = vec![0u8; KEY_LEN * pub_key_count];
 
         // encrypt keys