Smiling

Pască Tanti Vali (traditional Romanian cheesecake)

hritcu — Sun, 31 Mar 2013 19:00:17 +0000

Ingredients:

1kg of cottage cheese
or 1kg of sour cream
or 1/2kg of cottage cheese and 1/2kg of sour cream
8 eggs
50-100g raisins
250g sugar
half teaspoon of salt

Ingredients for the dough (only for the variants with sour cream):

75g butter or margarine
2-3 spoons of sour cream
1 egg
3 spoons of sugar
1 spoon of baking soda neutralized with lemon juice
flour proportional to the rest

Special equipment:

springform baking pan
handheld electric mixer/beater
Immersion blender

Preparation:

For the variants with cream you need to first make a soft dough. Once done put this dough in the fridge for 2 hours or so. Afterwards, take the dough out of the fridge, flatten it with a rolling pin and give it a round shape, then lay it on the bottom and sides of the springform pan, all the way up.
Blend the cottage cheese in a bowl with the immersion blender.
Separate the 8 eggs. Beat the egg whites and sugar with the electric mixer until stiff. Separately, mix the yolks with a bit of salt. Add everything to the cheese and homogenize.
Put the raisins into boiling water, boil for a bit, than take them out, and remove excess water. For the variants with cream pass the raisins through flour and gently lay them on top of the cheesecake. For the variant with just cheese put the raisins with everything else when homogenizing.
Pour everything in the spring form (over the dough if making a variant that requires dough).
Bake in the preheated oven for 60 minutes starting at 200 degrees Celsius but decreasing the temperature to 150 degrees Celsius towards the end. After it is done turn off the oven and leave the cheesecake inside until next day so that it cools down very slowly.

Tiramisu

hritcu — Sun, 31 Mar 2013 03:22:21 +0000

Ingredients:

6 egg yolks
6 spoons of sugar
400g lady fingers
400g Mascarpone cheese
500g whipped cream
2 small bags of vanilla sugar (2 x 7-9g)
some cacao
amaretto liquor
10 little cups of espresso (or decaf espresso, or instant espresso) mixed with 4 tea spoons of sugar

Equipment:

a high rectangular plastic/glass tray

Preparation:

Make the coffee, add the 4 tea spoons of sugar and let it cool down.
Stir the yolks with the sugar in a large container until the sugar melts, then add the cheese little by little.
Whip the cream in a separate container. Keep 1/3 of it for decorating and incorporate the remaining 2/3 little by little into the cream.
Pass the ends of the lady fingers quickly through the coffee, then put into the tray. Once you’re done with a complete layer of lady fingers pour half of the cream, then lay another layer of lady fingers rotated by 90 degrees (perpendicular wrt the first layer). Then put the other half of the cream and at the end the 1/3 of the whipped cream.
Put in the fridge for a couple of hours.
Before serving, put cacao on top through a small sieve.

Wealth Inequality in America

hritcu — Tue, 05 Mar 2013 14:19:28 +0000

I wonder how Europe compares to all this …

CFP: FCS’13 Workshop on Foundations of Computer Security

hritcu — Mon, 25 Feb 2013 14:27:36 +0000

My first PC membership

+---------------------------------------------------------+
!                                                         !
!			FCS 2013                          !
!       Workshop on Foundations of Computer Security      !
!     Tulane University, New Orleans, Louisiana, USA      !
!                     June 29, 2013                       !
!   http://prosecco.inria.fr/personal/bblanche/fcs13/     !
!                                                         !
!          Affiliated with LICS 2013 and CSF 2013         !
!                                                         !
+---------------------------------------------------------+

Important dates
===============

Submission:			April 10, 2013
Notification of acceptance: 	April 30, 2013
Final papers: 			May 31, 2013

Invited speaker: Boris Koepf, IMDEA, Spain
===============


Background, aim and scope
=========================

The aim of the workshop FCS'13 is to provide a forum for continued
activity in different areas of computer security, bringing computer
security researchers in closer contact with the LICS community and
giving LICS attendees an opportunity to talk to experts in computer
security, on the one hand, and contribute to bridging the gap between
logical methods and computer security foundations, on the other.

We are interested both in new results in theories of computer security
and also in more exploratory presentations that examine open questions
and raise fundamental concerns about existing theories, as well as in
new results on developing and applying automated reasoning techniques
and tools for the formal specification and analysis of security
protocols. We thus solicit submissions of papers both on mature work
and on work in progress.

Possible topics include, but are not limited to: 

Automated reasoning techniques
Composition issues
Formal specification
Foundations of verification
Information flow analysis
Language-based security
Logic-based design
Program transformation
Security models
Static analysis
Statistical methods
Tools
Trust management 	

for 	

Access control and resource usage control
Authentication
Availability and denial of service
Covert channels
Confidentiality
Integrity and privacy
Intrusion detection
Malicious code
Mobile code
Mutual distrust
Privacy
Security policies
Security protocols

Submission
==========

All submissions will be peer-reviewed. Authors of accepted papers must
guarantee that their paper will be presented at the workshop.
FCS'13 welcomes two kinds of submissions

  - short abstracts (1 page including references)
  - full papers (at most 15 pages including references) 

Short abstracts will receive as rigorous review as do full
papers. Short abstracts may receive shorter talk slots at the workshop
than do full papers, depending on the number of accepted
submissions. All papers should be written in the Springer LNCS style
available at the URL http://www.springer.de/comp/lncs/authors.html

The cover page should include title, names of authors, co-ordinates of
the corresponding author, an abstract, and a list of
keywords. Submissions that are clearly too long may be rejected
immediately. Additional material intended for the referees but not for
publication in the final version - for example details of proofs - may
be placed in a clearly marked appendix that is not included in the
page limit.

Authors are invited to submit their papers electronically, as portable
document format (pdf); please, do not send files formatted for word
processing packages (e.g., Microsoft Word or WordPerfect files). The
only mechanism for paper submissions is via the dedicated EasyChair
submission web page:

https://www.easychair.org/conferences/?conf=fcs2013

Please follow the instructions given there. 

Informal proceedings
====================

The workshop has no published proceedings. Presenting a paper at the
workshop should not preclude submission to or publication in other
venues. Copies of papers presented at the workshop will be made
available in electronic format, but this will not constitute an
official proceedings.

Program committee
=================

  * Myrto Arapinis (University of Birmingham, UK)
  * Aslan Askarov (Harvard University, USA)
  * Bruno Blanchet (INRIA Paris-Rocquencourt, France, co-chair)
  * Michael Clarkson (The George Washington University, USA, co-chair)
  * Sara Foresti (Universita` degli Studi di Milano, Italy)
  * Deepak Garg (Max Planck Institute for Software Systems, Germany)
  * Catalin Hritcu (University of Pennsylvania, USA)
  * Alan Jeffrey (Alcatel-Lucent Bell Labs, USA)
  * Peeter Laud (Cybernetica AS, Estonia)
  * Gurvan Le Guernic (DGA Maîtrise de l'Information, France)
  * Stephen Magill (IDA Center for Computing Sciences, USA)
  * David Naumann (Stevens Institute of Technology, USA)
  * Andrei Sabelfeld (Chalmers University of Technology, Sweden)
  * Santiago Zanella Béguelin (Microsoft Research Cambridge, UK)

Pâté à la Valironrons

hritcu — Sat, 23 Feb 2013 18:35:20 +0000

Here is a wonderful pâté recipe we have from our French friends. You need a meet grinder, but otherwise it’s not hard to make.

Ingredients (1 pound ~= 450g):

1 pound of chicken liver (or of any other poultry)
1/2 pound of bacon
1/2 pound of boneless pork
1 big bunch of parsley
1 egg
8g of salt (1/2 tablespoon)
and then, at wish: black pepper, garlic, mustard, coriander (cilantro), juniper, clove, pistachios,…

Preparation: Grind everything*, homogenize, and put in a rectangular baking dish. Cook in the oven in a bain-marie for about 1h:30min at 380F (~193C). Cool down before serving.

[*] Grinding chicken liver works best if it’s slightly frozen, otherwise the process is a bit messy.

All Your IFCException Are Belong To Oakland 2013

hritcu — Sat, 16 Feb 2013 13:41:31 +0000

Our paper marrying reliable exception handling and sound fine-grained dynamic information flow control was accepted at the IEEE Symposium on Security & Privacy (Oakland 2013).

All Your IFCException Are Belong To Us. Cătălin Hriţcu, Michael Greenberg, Ben Karel, Benjamin C. Pierce, Greg Morrisett.

Coq formalization and proofs are available here.
Breeze interpreter, libraries, and sample applications are available here.
A previous version of this work was called Exceptionally Available Dynamic IFC, July 2012.

Abstract: Existing designs for fine-grained, dynamic information-flow control assume that it is acceptable to terminate the entire system when an incorrect flow is detected — i.e, they give up availability for the sake of confidentiality and integrity. This is an unrealistic limitation for systems such as long-running servers.
We identify public labels and delayed exceptions as crucial ingredients for making information-flow errors recoverable in a sound and usable language, and we propose two new error handling mechanisms that make all errors recoverable. The first mechanism builds directly on these basic ingredients, using not-a-values (NaVs) and data flow to propagate errors. The second mechanism adapts the standard exception model to satisfy the extra constraints arising from information flow control, converting thrown exceptions to delayed ones at certain points. We prove that both mechanisms enjoy the fundamental soundness property of non-interference. Finally, we describe a prototype implementation of a full-scale language with NaVs and report on our experience building robust software components in this setting.

Learning/Teaching Coinduction with Coq

hritcu — Sun, 23 Dec 2012 19:03:47 +0000

This semester Benjamin Pierce gave a course on Advanced Coq Martial Arts based on Adam Chlipala’s CPDT book. The course was very interactive, with the students giving most of the lectures and being in charge of creating the exercises. Since I wanted to know more about coinduction I taught the coinduction lectures and learned a lot in the process. One of the results of these lectures is a new set of materials for teaching coinduction in Coq:

These materials are based on Adam’s book chapter, Giménez and Castéran’s tutorial, and Xavier Leroy and Herve Grall’s development on coinductive operational semantics. I’ve tried my best to explain things better and to add good exercises.

Another result is a new Coq tactic that allows for aggressive automation of coinductive proofs. Most of the easy proofs now take the form coind using coind_principle; crush.

Full Coq development including my coind tactic

Update 2012-12-25:

Here is the way I propose to marry co-induction and aggressive automation in Coq in these teaching materials. It’s actually all very simple. The primitive way of doing co-inductive proofs in Coq is by applying the cofix tactic directly. The guardedness check needed by cofix prevents effective automation. This problem is, however, not specific to co-induction: exactly the same problem appears when one uses fix directly in inductive proofs. Thus one very rarely uses fix directly in proofs. Instead, most often one proves lemmas encoding general induction principles (usually with lots of help from Coq) and then simply applies these principles with a bit of help from the induction tactic. What I propose is to apply this workflow that works very well for induction also to co-induction.

So instead of building proof terms directly with cofix one only uses cofix to define general co-induction principles. The co-induction principle for a co-inductive n-ary predicate P has the form:
forall R, (forall x1 ... xn, R x1 ... xn -> P_gen R x1 ... xn) -> forall x1 ... xn, R x1 ... xn -> P x1 ... xn
Where the predicate R seems very much related to the bisimulation proof technique and has the same type as P. The predicate “P_gen R” above is an variant of P where the recursive calls to P were replaced with calls to R.

Once one has proven such a general co-induction principle (and it’s usually very simple … my hope is that it can be fully automated as it is done for most induction principles) one can use it to write automated proofs by co-induction. The only remaining pain is that one has to manually choose an R whenever instantiating the co-induction principle. Here is where the coind tactic comes into play: it automatically instantiates R based on the syntactic shape of the goal (more details of how this works at the end of CoindStart
… it’s actually quite simple). The coind tactic doesn’t always choose “the right R”, but one can always strengthen the co-induction hypothesis in these cases. Again, things work very similar to induction, where the only way to strengthen the induction hypothesis is by changing the statement to be shown (not by fiddling with some R).

The German Ball Game

hritcu — Sat, 16 Jun 2012 15:10:19 +0000

Source: Games to train and relax body and mind
by Johann Christoph Friedrich GutsMuths, 1796
Translation by: Beate Brockmann
For further understanding and terminology check this out.

2. The German Ball Game

This game which has not yet been described anywhere merits very well a detailed description. It is not my goal to be entertaining in this endeavor – try just to understand these dry explanations, entertainment will be found in practicing.

Playing Field:
Drawing 1

Mark on a flat lawn the beginning point X and end point Z of the alley, approximately 30-40 steps apart, and the preparation is done; if you want to be more precise, rip the lines A-B and C-D with a pole/stick into the ground, and mark their ends and also the positions 4 and 5 with poles.

This way, also the width of the alley is defined.

Line A-B will be the batting plate (home plate), C-D the catching plate (“rest base”).

Ball: [This is a lengthy explanation how to produce the ball with material of 18th century Germany, giving several alternatives, and with the result of a ball that can jump 25 feet high if thrown down with force and is supposed to be nearly as good as a rubber ball]

Ballstock (Racquette): It is not good to take a broad-shaped piece of wood, as it resists the air and therefore the hitting cannot be as strong as with a completely round stick that gets thinner towards the handle, made from a trunk of a young spruce tree. Only with those you can successfully hit the ball to go up 80 to 100 feet and nearly 100 steps far. [And some other lengthy explanations how to prepare the handle so that it doesn’t easily fall out of the hand.]

Spiel: A team of eight, ten, twelve or more persons, no matter short or tall, gathers on the playground. The two best players will be appointed leaders, and are to arrange the game, arbitrate in case of disagreements etc. Their first duty is to divide the group in two parties rather equal in capacity. This is to be done following rules in the annex 1. Are both parties made, the decision which one is to be the ‘ruling’ (hitting – the “batting team”) and which one the ‘serving’ (catching – the “fielding team”) shall be made by throwing a coin (see annex1). Now the game can start. Both parties continuously fight against the other: the batting team tries to stay in the batting position; the fielding team tries to win the hit. This is the main idea of the game; but I will first develop the procedure of each team separately before explaining the general rules.

1) The fielding team
We suppose six persons for each team. At each start of the game and each time his team has lost the hitting position, the team leader positions his team in the positions 1, 2, 3, 4, 5 and 6, and the best players are to be put in 1,2,3,6 – because the side positions may be positioned with less able players, but 1 and 2 need to be able throwers, and 3 and 6 able catchers of the ball.

The person in position 1 is called pitcher; he must throw the ball for the batter. To this end he stays two steps in front of the batter who stands in E and throws the ball in the middle between himself and the batter upright in the air, a bit higher than the head. As the ball drops down, the batter has to hit him in the air. All other members of the fielding team in 2,3,4,5,6 have to try to get the ball as soon as possible into the batting plate, and therefore have to run to all sides to catch the ball and throw it to the pitcher. All of this has to be done quickly, therefore everyone should be able to catch and throw well, with right, left and both hands and in all positions, even in a run. The body will become very able, elastic and strong.

While doing this, the main goal of the fielding team is to change their status and switch to the batting position by winning the hit. This happens if a) a fielding team member catches the hit ball out of the air, b) if he throws the ball at a batter who is running from X to Y or back, and he hits him, c) if he can get the ball into the batting plate at a time when not batter is there anymore – the last two cases will be made more clearly in the following.

2) The batting team
They have the privilege to hit the ball, but each hit must be earned by the batter by running from the batting plate X to the resting base X and back.

As the batter cannot run while the ball is in the hands of a person of the fielding team who tries to hit him with the ball, he first has to hit the ball, or, if he fails that, to stay in the batting plate X and wait until one of the follow batters hits the ball and “loosens” him, only then he can run. If he arrives at the resting base Y, and the ball is still not near, he can right away run back to X. In the opposite case he remains behind the resting base Y until a good hit is done which loosens him to get back to the batting plate X.

It happens often that only one of all batters is left in the batting plate, because the others have not hit well or not hit the ball at all, and are therefore still standing in X or Y waiting to run. This last remaining batter is then called the “cleanup hitter”, as he tries to drive home all remaining base runners. He has the right to strike three times, while otherwise only one strike is permitted.

If the „cleanup hitter“ is a bad hitter, he might do his three strikes without hitting the ball; if this happens really without one of the home runners at Y managing by speed and artfulness to get to the batting plate, then the his is lost, because the ball gets to the batting plate without there being a “loosened” batter. The batting team will of course try to prevent that by trying with speed and artfulness to drive one of them into the batting plate, for instance by several of them running at the same time from different sides to the batting plate, and trying to divert the attention of the fielding team. Always try to have the “cleanup hitter” be a good hitter who rarely misses the ball.

At the beginning of the game, when the order of batting is not yet determined, the best batter stays behind and lets everyone else strike before him, so that he can “loosen” his team members. As the game goes on, the order of who will strike next will be defined by which player arrives first from Y to X – therefore the batting team has to make sure that from several players coming back to X the best one enters last, so that he can become “cleanup hitter”. For instance, if a, b, c are bad players and d is a good one, and all four were out at Y, and a strike would “loosen” them to come back to X, then d would have to let the other three get “home” first. Or if a, b, c were at Y and d, e f, as three good players, were still to do their batting in X, then a, b, and c would not be allowed to run “home” once a god hit has been done, but they would need to wait until one of the better three players comes out to Y – this good player has then again to come “home” last, to later become “cleanup hitter”.

The „cleanup hitter“ needs to be sure not to run after he dealt his first hit – other then if he could be sure that the waiting batters could for sure make it back to X from Y before the ball can be brought to the batting plate X. Imagine the “cleanup hitter” ran away after the first little hit, and the fielding party could bring in the ball before the batters come back from Y, the hit would be lost. Now the following rules for the players will be easy to understand.

1. Rules for the fielding team
a) Pitcher: His role is one of the most important, and he needs to be very able. He is the key position in the game, as he has to encourage the fielding team to pass him the ball and to make the batting team not lose time. Doing both, he keeps the game lively. His attention should be focused on
1- the current batter: if the current batter is inclined to send the ball regularly further away than the positions 4 and 5, the pitcher needs to change his position a bit as to prohibit that behavior. The better the pitcher throws the ball for the batters and adapts to their particularities, the more good hits will be done, and the better those hits can be caught by the fielding team.
2- the ball: often, the batter will hit the ball only on the quarter or in its eighth part and sends it only slightly up – these kind of balls the pitcher needs to catch to win the hit.
3- the batters of the batting team in general: he needs to strive to hit with the ball everyone who runs away from X or returns from Y either by himself, or to throw the ball to his team member in position 2, in case this person is nearer to the running batter, so that team member 2 can hit the batter. The pitcher also has to watch the batters standing in X; in case they pass the line A-B with as much as a single foot he has the right to throw the ball at this foot, and even more they trespass the line completely. In case the pitcher hits in such a case, he has won the hit.
4- to himself: he has to step back at least one wide step in the moment where the batter strikes, so as not to be hit by the raquette.
b) The other members of the fielding team have to watch carefully and at all times the ball and the batters. They have to know the habits of each batter – how far, in which directions they drive the ball. In case they predict the ball to come to their position, they have to be even more careful. Each time the ball is hit and gains height, they have to calculate the arch in which it will come down again, and try to quickly reach that spot to catch the ball and either hit one of the runners of the batting team or to pass the ball to a player who is better positioned to hit a runner.
If none of these cases is possible, the players of the fielding team pass the ball to the pitcher, to make the game continue.
Each member of the fielding team also keeps an eye on the lines A-C and B-D to check whether one of the runners of the batting team trespasses them – if this happens, their hit is lost. They should also notice if no “loosened” batter is in the batting plate anymore, because in this case they have to get the ball into the batting plate – this action has to be announced to everyone so that it can quickly be carried out without a batter reaching the batting plate first. Of course, if the ball arrives before the batter, the batting team has lost this hit.

2) Rules for the batting team
None of the batting players should run while the ball is held by one of the nearer players of the fielding team, as the chances are too high he could be hit by the ball and lose the hit. Only then is he allowed to run if there is no good batter in the batting plate anymore who could loosen the other players.
Each player needs to strive to hit the ball well and with strength, because small and week hits will be caught too easily. He has to be able to strike the ball into each direction he wants, and needs to choose the direction in which no good catcher is positioned. Also, he should never drive the ball to Y if his fellowmen are running in this direction, and by all means drive the ball to Y if his fellowmen are running in the opposite direction, towards X the batting plate. In short, he has to take care to drive the ball in such a way that it is far from his teammates, so as to minimizing their risk of being hit by the ball. Of course, if a batter can drive the ball further than the position 6, that would be an ideal solution.
If the ball threatens to hit a batter, the batter must be quick to avoid it – therefore he always looks around him and prefers to go down than to be hit. But the batter must take all the risk to get to the batting plate in the case of the “cleanup hitter” having only one hit left. Of course, the batters also need to make sure they don’t step over the sidelines of the field.

I finish the explanation with a general rule set for this game.

1) Each team has to follow its team leader. If there is a controverse about if a hit has been lost or not, and no agreement can be reached, it will be decided by lot.

2) Who ever goes down loses the hit of his team, if he is a batter. Is he who goes down a fielding team player, his party has to win twice before switching roles and becoming batting party. As punishment, the one who was laying on the ground is not allowed to strike in the next term, but still has to run with the team leader from X to Y and back.

3) If the game changes too often, meaning it is won too often from one, then the other team, one can decide that the fielding team needs to win two or three times in a row before they can become the batting team.

4) No batter is obliged to hit a ball which the pitcher has badly thrown. If no batter is satisfied with the balls a particular pitcher throws, they can ask the fielding team to put a better pitcher in place. If the “cleaning hitter” is about to do his third strike, he is allowed to not strike at all but on purpose let the ball drop, so that the ball is out of the hands of the pitcher for a moment, but he can only do so twice.

5) The series of strikes a team does before they lose the right to strike is called a „Gang“. In order to find out which team has won the game at the end, each team has to count the strikes done aloud and note them after the “Gang” on a blackboard. Small strikes that do not reach higher than a man will not be counted. At the end of the game, when both teams have played the same number of “Gaenge”, all strikes will be added and the team who has the higher number of them has won.

6) A strike gets lost if:
a) If a player of the fielding team catches the ball out of the air. Has the ball already touched the ground, this is not the case – but if the ball has just bounced back from a person or an object, the catch out of the air is still valid.
b) If any player of the batting team gets hit by the ball in between A B C D, no matter under which circumstances. However, the pitcher is not allowed to partake in this throwing if he is inside of the playing field – he has to remain in front of the line A-B, because If he was allowed to partake in hitting the players of the batting team with the ball, he could run after each of them who is slower than he is, catch up with him and hit him, while the other is trying to run from X to Y to get “loosened”.
c) If a player of the fielding team throws the ball into the batting plate while there is no batter present on the batting plate.
d) If a player of the batting team crosses the lines A-C or B-D.
e) If a „cleaning hitter“ has done his three strikes and after the third strike the ball gets quicker into the batting plate than a new batter. This is the same case as c) and happens most often in case the third strike is not hit and the ball falls down in front of the line A-B.
f) If a player of the batting team touches the ball.
g) If a player of the batting team takes the raquette from the batting plate into the playing field on his run from X to Y.
h) If a player of the batting team, after striking, throws away the raquette so quickly and carelessly that one of the other players is hit.
t) If a player of the batting team drops the raquette while striking.

7) If the hit is won by the fielding team, the winner has the right to do the first strike, after him the former pitcher has the right to strike, after this one all of the others no matter in which order. But afterwards, as the game goes on, the order in which the players strike is determined in the order in which they come in from Y. If the case happens that a bad batter is the last one to come in and would normally become “cleaning hitter”, the fielding team is not obliged to accept that this bad batter may strike before to have a better batter become the “cleaning hitter”.

8) The ball is never carried by hand, but has to be thrown from player to player, and then caught out of the air.

From all games for young people, this is one of the best, because it fulfills several goals of physical games. It favors much moving in the open air, and furthers the body’s speed, promptness and strength. Batting and throwing gives ability and strengths to the arm and the running makes flanks and legs quicker. Avoiding to be hit by the ball makes it necessary to be very quick. Also the visual judgment is trained during this game, for instance for hitting the ball the pitcher has thrown, or for hitting a running batter, or for catching the ball out of the air – and this while the ball goes in arches of 70 feet high and 80 steps wide. The game asks for constant attention and brings so much pleasure and interest for young people who are not effete that they will prefer it to any other game, during spring time.

I already said that this game can be played by more and fewer people, even with just 4 persons. This last version which is called “Fourball” is a lot more intense because those four persons have to do just as much as the twelve as described above. Also here, one of the fielding team is the pitcher, the other one stands outside, and one batter becomes the “cleaning hitter” for the other hitter.

Nicuşor Dan reaprinde speranţa pentru Bucureşti

hritcu — Thu, 31 May 2012 13:28:13 +0000

Nicuşor Dan pentru Bucureşti

hritcu — Thu, 03 May 2012 19:21:01 +0000

Clarke’s three laws

hritcu — Sat, 28 Apr 2012 16:22:51 +0000

When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong.
The only way of discovering the limits of the possible is to venture a little way past them into the impossible.
Any sufficiently advanced technology is indistinguishable from magic.

Source: Wikpedia

Research Ranking of Romanian Universities 2011

hritcu — Mon, 11 Jul 2011 15:51:16 +0000

The “Alexandru Ioan Cuza” University from Iaşi scored second in the 2011 Computer Science scientific results ranking:

Universitatea Babeş-Bolyai, Cluj Napoca
Universitatea Alexandru Ioan Cuza, Iaşi
Universitatea Valahia, Târgovişte
Universitatea Bucureşti, Bucureşti
Universitatea Politehnica Bucureşti

As always take this ranking with a big grain of salt.

Expi2Java 1.6 Released

hritcu — Fri, 13 May 2011 19:36:14 +0000

Alex Busenius and me are pleased to announce that Expi2Java 1.6 was released two days ago. And by the way, Alex has recently finished his MSc and is looking for a job in industry. If you know anything interesting in a German or English speaking country, please let him know.

Expi2Java 1.6 was released yesterday (11.05.2011)

The highlights of this release are the new symbolic library and a mechanized formalization in Coq.

The symbolic library abstracts away cryptographic primitives as symbolic terms and networking as pi-calculus-like channels. It is designed to be sound and simple enough to simplify proving the transformation secure. Both the symbolic and concrete libraries can be used interchangeably with all provided examples.

We have formalized the transformation from Expi Calculus to a subset of Java performed by Expi2Java using the Coq proof assistant and proved the symbolic library and the produced Java code to be well-typed. The formalization and all proofs can be found on the project homepage.

The full list of changes:

Removed support for user-provided imports. All implementation classes should be included into the used implementation library

Refactored concrete library

A symbolic library can now be generated from the provided configuration

Both concrete and symbolic libraries can be used interchangeably with all provided example protocols

New restrictions for the type of constructors:

The return type can no longer be a type variable

All type variables used in the type of an Expi constructor must appear in its return type

Return type can no longer be Top (unimplementable)

Constructors used in the destructor declarations must always be annotated

Changes to the type inference algorithm:

The variables from the right side of the reduction rule are no longer used to infer type of the variables on the left side of the reduction rule

More precise type inference in some cases

Changed the set of default types

Merged Expi types String and ConstString to ExpiString

Changed variance of some default types to avoid problems with destructor inconsistency

As always, an updated version of the documentation is available as well.

Please take a look at the project homepage for more details and download links:
http://www.infsec.cs.uni-sb.de/projects/expi2java

Best regards,
Alex

Inside Job

hritcu — Mon, 28 Feb 2011 16:13:29 +0000

Inside Job, a great documentary about the financial crisis by Charles H. Ferguson. The film won the Oscar for Best Documentary Feature yesterday.

Despre “Alianța Grivco” și necesitatea unei alternative reale

hritcu — Wed, 12 Jan 2011 22:56:52 +0000

Nu mi se pare deloc justă retorica de sorginte mogulistă conform căreia actuala putere este singura vinovată pentru toate problemele actuale, mai ales cele economice^1, iar coalizarea opoziției actuale reprezintă singura salvare de la acest dezastru^2. Ideea eu o consider complet greșită, pentru că opoziția actuală din Parlament nu e cu nimic mai presus decât actuala putere, ci dimpotrivă, ambele sunt un dezastru pentru România.

În afară de “soluția” Iohannis, care încerca să se folosească de popularitatea unui singur om pentru a ne băga pe gât același lucru pe care l-am înghițit până acum, ce alte soluții a prezentat până acum actuala opoziție? Din punct de vedere economic “soluția” PSD e impozitarea progresivă, deși cel mai probabil asta ar scădea nu spori încasările la buget. Asta în timp ce PNL+PC susțin păstrarea cotei unice de 16%. Consens maxim pe această problemă! La fel conses maxim între PNL și PC pentru creștere de 25% pe an și alte povești de adormit copiii.
În rest, încrâncenare maximă la orice propunere a puterii, chiar și la puținele care sunt rezonabile. Vezi de exemplu circul făcut de PSD cu legea educației, o lege pregătită în mare parte de PSD când era la putere împreună cu PDL și bazată pe un pact al educației pe care Mircea Geoana l-a semnat când încă era președinte al PSD. Coerență maximă! Nici nu trebuie să mai spun despre cât de jalnică e actuala putere, pentru că propagandă mogulistă prezintă deja asta în cel mai mic detaliu. La fel nu mai trebuie să menționez cât de corupți sunt cu toții, știm asta prea bine.

Din această cauză, eu cred că pentru o schimbare în bine a clasei politice românești ar trebui să apară partide noi și să le înlocuiască în timp pe cele existente. Unul din aceste partide noi care ar putea avea succes este Mișcarea Verzilor — eu cel puțin sper sincer acest lucru. Un altul (partidul Alba ca Zăpada?) ar putea să se rupă din PDL odată cu plecarea Monicăi Macovei și a lui Cristi Preda (eu nu cred că vor mai rezista mult în mult prea coruptul PDL). Un altul ar putea veni dinspre societatea civilă, de exemplu SAR și Alina Mungiu-Pippidi ar putea să încerce să se implice mai direct în viața politică. Sau poate Cristian Ghinea să se încumete să facă “Partidul Pentru Politici Europene“? Deși acestea nu sunt decât speculații, astfel de alternative ar aduce ceva diferit față de ce se întâmplă deja pe scena politică românească. Depinde numai de noi dacă vrem să ne mulțumim doar cu o “rotații de cadre” între putere și opoziție făcute în speranța că românii au memoria foarte scurtă, sau dacă vrem să creăm sau să sprijinim alternative reale.

^1 Oricât de prost a gestionat Boc criza economică, nu a adus-o el peste România (în același fel cum nu a adus-o Obama pe cea din SUA), și măsurile populiste luate de toate partidele nu ne-au ajutat deloc să fim pregătiți pentru această criză. E foarte ușor să mărești electoral cheltuielile pe datorie în speranța că va fi boom forever și n-o să se prindă nimeni. Din păcate n-a fost! Costul electoral nu-l plătește însă decât PDL.

^2 Comparația pe care am văzut că unii o fac între CDR și “Alianța Grivco” nu e deloc perfectă. Într-adevăr, ambele au fost/sunt alianțe împotriva unui partid care risca/riscă să monopolizeze spațiul politic (atunci FSN/PDSR/PSD, acum PDL). Într-adevăr, ambele au fost sau sunt alianțe între dreapta și stânga, deci fără o bază doctrinară solidă. Marea diferență e că CDR promitea schimbarea aducând oameni și idei noi la putere, o putere până atunci acaparată de FSN/PDSR. Nu le-a prea reușit CDR-iștilor, dar măcar a fost o încercere de a schimba ceva. Prin contrast Alianța Grivco nu mi se pare decât o încercare de “rebranding” a unor partide depășite care și-au demonstrat deja inabilitățile pe toate planurile, și care nu s-au schimbat câtuși de puțin.