Fixed some more stuff

1 files changed, 14 insertions, 4 deletions

diff --git a/draft-summermatter-set-union.xml b/draft-summermatter-set-union.xml
index 869596c..1eb7a0d 100644
--- a/draft-summermatter-set-union.xml
+++ b/draft-summermatter-set-union.xml
@@ -1166,14 +1166,24 @@ hashSum |    0x0101   |    0x0101   |    0x5050   |     0000    |
                                 Its important that the elements can be redistributed over the buckets in case the IBF does not
                                 decode, that's why the ID is salted with a random salt given in the SALT field of this message.
                                 Salting is done by calculation the a random salt modulo 64 (using only the lowest 6-bits of the salt)
-                                and do a bitwise right rotation of output of KDF by the 6-bit salts numeric representation.
+                                and do a bitwise right rotation of output of KDF by the 6-bit salts numeric representation. To
+                                get the IDSUM field all IDs who hit a bucket are added up with a binary XOR operation.
                             </t>
                             <t>
                                 The HASH is calculated by calculating the CRC32 checksum of the 64-bit ID value
-                                which returns a 32-bit value. This is calculated modulo the count of buckets to
-                                ensure that it is a valid bucket index. Create a new 64-bit value by shifting the 32-bit
-                                value left and setting the lower 32-bit....
+                                which returns a 32-bit value. To get the HASHSUM field all IDs are added
+                                up with a binary XOR operation.
 
+                            </t>
+                            <t>
+                                To decide in which buckets the ID and HASH have to be added up there is the following
+                                algorithm used: The first index is simply the HASH modulo the IBF size. The second
+                                index is calculated by creating a new 64-bit value by shifting the 32-bit
+                                value left and setting the lower 32-bit to the number of indexes already processed. From the
+                                resulting 64-bit value a CRC32 checksum is created the second index is now the modulo of the
+                                CRC32 output this is repeated until the predefined amount indexes is generated.
+                                In the case a index is hit twice, which would mean this bucket could not get pure again,
+                                the second hit is just skipped and the next iteration is used as.
 
                                 <!-- @Christian: I dont have a clue how this is done... The code is very hard to read can you explain the
                                  salt_key function in gnunet-service-set_union.c file