X-Git-Url: http://www.git.cypherpunks.ru/?a=blobdiff_plain;f=README;h=d16ccebf98188a061c0e3da10448e99085ab5648;hb=c1f422272e2a54b19488ce5bdc4a14109bc2443f;hp=a307e8d7fea5aceb2c180379d8338851c12a5a8f;hpb=915a46b16cf4f61778e4b30364e299026656a60e;p=gohpenc.git

diff --git a/README b/README
index a307e8d..d16cceb 100644
--- a/README
+++ b/README
@@ -1,13 +1,19 @@
 Go high-performance encryption utility.
 
 gohpenc highly resembles hpenc tool (https://github.com/vstakhov/hpenc).
+hpenc solves the problem that there is no simple tool to quickly
+transfer data with encryption and authentication:
 
-Why it was written? hpenc has some problems: it does not work on aarch64
-and sparc64 architectures under FreeBSD (as seen in the port's Makefile)
-and produces incompatible output (unauthenticated after 8192 blocks)
-between FreeBSD and HardenedBSD systems somehow. Instead of painful
-debugging I decided to write something similar on the Go language,
-widening supported platforms.
+* openssl enc -- uses single CPU, no authentication
+* GnuPG -- complex key generation/management, relatively slow
+* OpenSSH -- uses single CPU, not very fast
+
+Why gohpenc was written? hpenc has some problems: it does not work on
+aarch64 and sparc64 architectures under FreeBSD (as seen in the port's
+Makefile) and produces incompatible output (unauthenticated after 8192
+blocks) between FreeBSD and HardenedBSD systems somehow. Instead of
+painful debugging I decided to write something similar on the Go
+language, widening supported platforms.
 
 gohpenc is incompatible with hpenc and much simpler:
 
@@ -27,9 +33,16 @@ But it still satisfies most of hpenc aims:
   dependent libraries contain assembly-optimized code
 * Built-in authentication and integrity check with small data overhead
 
+Usage is very simple:
+
+    $ gohpenc -psk
+    DTGZI5R2HS4YEDSIO56AFKPONE6KJE3Q2QETODDOH3O6UYFPROHQ
+    $ echo "message to be transmitted" | gohpenc -k DTGZI5R2HS4YEDSIO56AFKPONE6KJE3Q2QETODDOH3O6UYFPROHQ > encrypted
+    $ gohpenc -k DTGZI5R2HS4YEDSIO56AFKPONE6KJE3Q2QETODDOH3O6UYFPROHQ -d < encrypted
+
 How encryption/authentication is performed:
 
-* First 32 bytes of the stream contains random data, called salt
+* First 32 bytes of the stream contain random data -- salt
 * BLAKE2X is initialized: unknown length, PSK key as a MAC key. It
   creates XOF that will be used as a KDF
 * Salt is fed into that XOF
@@ -45,9 +58,10 @@ How encryption/authentication is performed:
 | SALT | LEN | CIPHERTEXT | AUTH TAG | LEN | CIPHERTEXT | AUTH TAG | ...
 +------+-----+------------+----------+-----+------------+----------+----
 
-gohpenc preallocates memory for one block for each thread. If you want
-to process data with 1 MiB blocks in 4 threads, then you have to have at
-least 4 MiBs of free memory. Moreover you have at least 1 MiB of free
-memory on the decrypting side.
+gohpenc preallocates memory for one block for each thread and one block
+for buffered reading from stdin. If you want to process data with 1 MiB
+blocks in 4 threads, then you have to have at least 5 MiBs of free
+memory. Moreover you have at least 1 MiB of free memory on the
+decrypting side.
 
 gohpenc is free software: see the file COPYING for copying conditions.