diff --git a/AUTHORS b/AUTHORS
index 69bbfc3e..c4fbdc0b 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -9,10 +9,8 @@ Authors of XZ Utils
     specifically the LZMA SDK <https://7-zip.org/sdk.html>. Without
     this code, XZ Utils wouldn't exist.
 
-    The SHA-256 implementation in liblzma is based on the code found from
-    7-Zip <https://7-zip.org/>, which has a modified version of the SHA-256
-    code found from Crypto++ <https://www.cryptopp.com/>. The SHA-256 code
-    in Crypto++ was written by Kevin Springle and Wei Dai.
+    The SHA-256 implementation in liblzma is based on code written by
+    Wei Dai in Crypto++ Library <https://www.cryptopp.com/>.
 
     Some scripts have been adapted from gzip. The original versions
     were written by Jean-loup Gailly, Charles Levert, and Paul Eggert.
diff --git a/src/liblzma/check/sha256.c b/src/liblzma/check/sha256.c
index 6feb3425..9247fa32 100644
--- a/src/liblzma/check/sha256.c
+++ b/src/liblzma/check/sha256.c
@@ -2,18 +2,12 @@
 //
 /// \file       sha256.c
 /// \brief      SHA-256
-///
-/// \todo       Crypto++ has x86 ASM optimizations. They use SSE so if they
-///             are imported to liblzma, SSE instructions need to be used
-///             conditionally to keep the code working on older boxes.
 //
-//  This code is based on the code found from 7-Zip, which has a modified
-//  version of the SHA-256 found from Crypto++ <https://www.cryptopp.com/>.
-//  The code was modified a little to fit into liblzma.
+//  The C code is based on the public domain SHA-256 code found from
+//  Crypto++ Library 5.5.1 released in 2007: https://www.cryptopp.com/
+//  A few minor tweaks have been made in liblzma.
 //
-//  Authors:    Kevin Springle
-//              Wei Dai
-//              Igor Pavlov
+//  Authors:    Wei Dai
 //              Lasse Collin
 //
 //  This file has been put into the public domain.