The strings generated by this library are meant to be pretty, not secure. It is not a secure way of representing a hash as many collisions are possible.
The strings generated by this library are meant to be pretty, not secure. It is not a secure way of representing a hash as many collisions are possible.
*** Digest algorithm
*** Digest algorithm
The kana algorithm is a 16-bit block digest that works as follows:
The kana algorithm is a 16-bit block digest that works as follows:
- The most and least significant 8 bits are each seperated into /Stage 0/ and /Stage 1/ each operating on the first and second byte respectively.
- The most and least significant 8 bits are each seperated into /Stage 0/ and /Stage 1/ each operating on the first and second byte respectively.
- Stage 0:
- Stage 0:
1. The byte is sign tested (bitwise ~AND~=0x80=), store this as a boolean in /sign0/.
1. The byte is sign tested (bitwise ~AND~=0x80=), store this as a boolean in /sign0/.
2. The valid first character range is looked up using the result of the sign test (either 0 or 1), store the range in /range/, and the slice ~KANA~ taken from the range in /kana/.
2. The valid first character range is looked up using the result of the sign test (either 0 or 1), store the range in /range/, and the slice ~KANA~ taken from the range in /kana/.
3. The first index is calculated as the unsigned first byte modulo the size (exclusive) of /range/. Store this as /index0/.
3. The first index is calculated as the unsigned first byte modulo the size (exclusive) of /range/. Store this as /index0/.
4. The swap table is checked to see if /index0/ has an entry. Then each following step is checked in order:
4. The swap table is checked to see if /index0/ has an entry. Then each following step is checked in order:
+ If the swap entry exists and the first byte bitwise ~AND~=0x2= is not 0, set the first character of the output to the value found in the swap table.
+ If the swap entry exists and the first byte bitwise ~AND~=0x2= is not 0, set the first character of the output to the value found in the swap table.
+ If the swap entry exists and the first byte bitwise ~AND~=0x8= is not 0 and the index has an entry in the 2nd swap table, set the first character of the output to the value found in the 2nd swap table.
+ If the swap entry exists and the first byte bitwise ~AND~=0x8= is not 0 and the index has an entry in the 2nd swap table, set the first character of the output to the value found in the 2nd swap table.
+ In any other case, set the first character of the output to the value found in the /kana/ slice at the /index/.
+ In any other case, set the first character of the output to the value found in the /kana/ slice at the /index/.
- Stage 1:
- Stage 1:
1. Compute a sub table for /index/ plus the start of /range/ using the ranges defined in ~KANA_SUB_VALID_FOR~ and store it in /sub/. If there is no sub table possible, skip to step 3.
1. Compute a sub table for /index/ plus the start of /range/ using the ranges defined in ~KANA_SUB_VALID_FOR~ and store it in /sub/. If there is no sub table possible, skip to step 3.
2. If there is an entry in /sub/ for the index of the 2nd byte modulo the size of ~KANA_SUB~, set the second output character to be that character.
2. If there is an entry in /sub/ for the index of the 2nd byte modulo the size of ~KANA_SUB~, set the second output character to be that character.
3. If there was no value set from the sub table, the 2nd output character becomes the first output character from inputting the 2nd byte back through /Stage 0/ as the first byte.
3. If there was no value set from the sub table, the 2nd output character becomes the first output character from inputting the 2nd byte back through /Stage 0/ as the first byte.
- Concatenate both characters and move to the next 16-bit block.
- Concatenate both characters and move to the next 16-bit block.
Notes:
Notes:
- It is valid for a single iterator to produce between 0 and 2 characters but no more.
- It is valid for a single iterator to produce between 0 and 2 characters but no more.
- If an input given to the algorithm that cannot be divided exactly into 16-bit blocks (i.e. one byte is left over), a padding byte of 0 is added as the 2nd byte to make it fit.
- If an input given to the algorithm that cannot be divided exactly into 16-bit blocks (i.e. one byte is left over), a padding byte of 0 is added as the 2nd byte to make it fit.
For more information see [[file:./src/mnemonic.rs][mnemonic.rs]].
For more information see [[file:./src/mnemonic.rs][mnemonic.rs]].
