scyther/src/notes.txt

- If no attack/state output is needed, maybe the attack heuristic should
  be simpler (which means just weighting the trace length etc.) in order
  to avoid uneccesary continuation of the search. Maybe even stop
  altogether after finding *an* attack.
- For the TimeStamps etc, we can implement an 'auto-leak' of such local
  constants. This should works also with a modifier of sorts (e.g.
  'predictable') and such constants should be leaked to the intruder at
  the start of the run, possibly by prefixing a send.
- The trace incremental search should start at something like 'distance of
  first claim + SOMECONST * runs'. SOMECONST relates to the partial-order
  induced trace prolonings.
- For now, CLP is non-working and not checked. Reconsider this later.
- Because the properties checked are related to the partial order reductions,
  it makes sense to check 'all secrecy claims' or 'all synchronisation claims'
  at once.
- Given originator assumptions and such, we might want to implement the
  compiler, that for non-typed matching, it will ignore all type definitions
  in the code (as in, putting them in stype, but still considering Function).
  Then, for 'any agent' we can use stype silently. The modelchecker should
  then always consider the types with -m0 and -m1.
- In a paper concerning the CASRUL compiler, they mention associativity for
  the equality relations.  Note that CASRUL restricts the intruder actions,
  and sometimes uses approximations.
- MS and CE never mention associativity as a restriction.
- For now, clp stuff will use pairing and simple mgu. Maybe a -m3 switch will
  add the associative variant later.
- MALLOC_TRACE is the environment variable that triggers mtrace() output.
- Several memory leak detectors are still in place, they can all be located by
  searching for "lead" or "diff" and destroying the code.
- knowledgeAddTerm might be improved by scanning through key list only with
  things that are newly added.
- Associativity and unification don't play together well; consider other
  algorithms. Maybe a simple explore (x,y),z and explore x,(y,z) will do, e.g.
  take any split point for both sequences.
- POR (-t3) is actually worse than -t2: sends first. After some pondering I
  now know why. It's because simultaneous reads yield traces in which there
  are attacks that are also in the ones where we have R0S0S0;R1 (i.e. is thus
  equivalent with R0;R1;S0S0)
- Knowledge is monotonous. So, if we say 'R#0' cannot be triggered by some
  knowledge, we can just use a pointer for it. If we do want to trigger it, we
  need to compare two knowledge pointers. As they don't have a unique
  representation, it is more difficult. For now, I will just forbid specific
  branches of the read when a message is in some previous knowledge, which is
  more precise.
- Comparisons with Casper are in order.
- It is a good idea to have any number of input files, and parse them all, to
  combine scenarios. A command should be "require <file>", because that would
  enable scenarios to load the required role definitions. It's require instead
  of include, because of possible multiple occurrences.