crypto/ecdsa: improve documentation readability

Include references in the package-level comment block, expand
the obscure IRO acronym, and add a reference for "the standard
(cryptographic) assumptions".

Fixes #33589

Change-Id: I76c3b0a2f7258b3ab4bf1c8e7681c5d159720a20
GitHub-Last-Rev: 30d5a1e2fbbbb577ccc819f5ef80d5238565c9f3
GitHub-Pull-Request: golang/go#33723
Reviewed-on: https://go-review.googlesource.com/c/go/+/190840
Reviewed-by: Filippo Valsorda <filippo@golang.org>

diff --git a/src/crypto/ecdsa/ecdsa.go b/src/crypto/ecdsa/ecdsa.go
index ddc3b35ba30336c0618746bb364d151d9b57576b..d1c7975aa93157104597418a59f1eb7f23493620 100644 (file)
--- a/src/crypto/ecdsa/ecdsa.go
+++ b/src/crypto/ecdsa/ecdsa.go
@@ -5,13 +5,23 @@
 // Package ecdsa implements the Elliptic Curve Digital Signature Algorithm, as
 // defined in FIPS 186-3.
 //
-// This implementation  derives the nonce from an AES-CTR CSPRNG keyed by
-// ChopMD(256, SHA2-512(priv.D || entropy || hash)). The CSPRNG key is IRO by
-// a result of Coron; the AES-CTR stream is IRO under standard assumptions.
+// This implementation derives the nonce from an AES-CTR CSPRNG keyed by:
+//
+// SHA2-512(priv.D || entropy || hash)[:32]
+//
+// The CSPRNG key is indifferentiable from a random oracle as shown in
+// [Coron], the AES-CTR stream is indifferentiable from a random oracle
+// under standard cryptographic assumptions (see [Larsson] for examples).
+//
+// References:
+//   [Coron]
+//     https://cs.nyu.edu/~dodis/ps/merkle.pdf
+//   [Larsson]
+//     https://www.nada.kth.se/kurser/kth/2D1441/semteo03/lecturenotes/assump.pdf
 package ecdsa
 
-// References:
-//   [NSA]: Suite B implementer's guide to FIPS 186-3,
+// Further references:
+//   [NSA]: Suite B implementer's guide to FIPS 186-3
 //     https://apps.nsa.gov/iaarchive/library/ia-guidance/ia-solutions-for-classified/algorithm-guidance/suite-b-implementers-guide-to-fips-186-3-ecdsa.cfm
 //   [SECG]: SECG, SEC1
 //     http://www.secg.org/sec1-v2.pdf