Schneier on Security

Clive Robinson • May 27, 2022 6:18 AM

@ JonKnowsNothing,

This is during the hottest part of the day and at time when people are accustomed to having dinner == cooking.

The way we cook is generally very wasteful of energy.

Annoyingly cutting the energy waste whilst technically easy, it’s not that easy for most to do.

Back in the 1950’s for instance you could get “cookers” that had heat insulating covers you could lower down. So you put a pan of vegetables on and brought to the boil. You then turned off the heat and lowered the cover. The food continuined to cook without other energy input for quite a period of time an hour or more being normal. This would cut your energy input down to a third or less in return for taking the “cooking time” from 1/3rd of an hour to about an hour and a half. The food will remain at a hot eating temprature for atleast as long again. So you could start cooking around 3:40pm stop using energy before 4pm and still eat a hot meal some time after 6pm.

The insulating covers idea was not exactly an original idea but was kind of a “high tech” implementation for the 1950’s. However the down side is those covers were made with white asbestos, not exactly something most people would want around especially near food.

The idea however goes back centuries to the use of “hot stone pit” (steam/luau), cauldron, and hay box cooking. You use a “heat storage” element and “insulation”, it’s most efficient if the storage element is what you are cooking, especially if it has a very high water content.

Thus soups, stews and steamed pudings etc. Not everybodies favourites I know but generally healthy and importantly helps you get the most benifit from the food so effectively makes it go 10-20% further.

Put simply if you cook complex cards and proteins long and slow it’s like having a second stomach to assist in digesting. Likewise lipids and minerals that are essential, all become more available for digestion, as for fiber, likewise it makes it more benificial and life more satisfactory.

The modern fancy way is “waterbath cooking” known as “Sous Vide”. The tenprature controled water bath and vacuum sealed bags of food work the same way as a cauldron with a low fire under it and food in pots or cloths hung in the water from the rim. To prevent leakage from the cloths they are first wetted then the inside dusted with fine flour then a heavy suet layer into which the food is sealed. The cloth is then tied up to make a “puding” that then cooks over five to ten hours. See discussions on cooking “steamed pudings” to get the fine details. The “all around heat” effect is also why “Dutch ovens” look like little cauldrons with lids, you make a fire in a sunken harth or pit, and when it is just glowing coals you scrape them aside sufficient to get the “dutchy” in then pile the coals up and over it then “bankup” with earth to keep the heat in.

But rather than go very “old witches school”, “50’s fab-estos” or ultra modern “stainless steel sous vide” is there anything else you can do?

Well yes is the answer, and make your own “hay box” with a large box, two “contracors bags” and an old duvet and pillow.

Basically put the box on the floor and put one contractor bag inside it, which you then line with the duvet and put the second contractor bag inside of that. In essence you are making the equivalent of a hot water tank insulating jacket. Inside of this add a small wooden board or similar you can stand a sauce pan with lid but without long handles on. When the pan is level you fold the inner contractor bag over it put the pillow on-top then pull any excess duvet over that and fold the outer contractor bag over that and put a small light weight on-top to keep it in place. Thus you have your insulated hot water tank for cooking.

The trick to doing hay box cooking is to work out energy curve to cook a particular food stuff. With root vegtables and the like I generally assume equal weight of boiling water and let slow cook down to 50-60C or atleast three hours, but the slower the temprature drop and the longer the time generally the better.

So get your sauspan and put only a small amount of water in the bottom then small chop the vegtables and add to it, put on the lid, and put on a low heat to bring to the point it is just lightly steaming. In a kettle bring to the boil the equivalent weight of water, then add thist to the saucepan put on the lid and put in your hay box and then go and do other things for three hours.

If all has gone right, the saucepan will still be above 60C and the vegtables will be softly cooked.

A simple chunky vegtable soup can be made by putting an inch of chopped carrot as the bottom layer, two inches of chopped potatoes and an inch of thin choped onions on that and add a stock cube to the steaming water.

Experiment with vegtables you can eat raw untill you get the hang of it that way you don’t waste anything if it’s under cooked.

Most “slow cooker” recipies will work.

One thing to remember, if you hay box cook but it gets two cool/cold to eat if you lift the cooked food out of the liquid with a slotted spoon you can heat it in just a few seconds in the microwave and heat just enough of the stock in a glass jug and add fresh choped light herbs to add extra flavour, and a little plain flour, corn flour, or arrow root to lightly thicken which helps hold it in your stomach for longer making it feel like you have eaten more.

Abother trick worth remembering is batter is water, fat, flour, and eggs in various ratios. Anything that is nearly all eggs is scrambled eggs, or if smooth a custard as you thin it out with more fluid it becomes batter for things like “toad in the hole” thinner yet Yorkshire pudding mixture, through pan cake mixture through to creep mixture.

Whole milk is basically water with fat in it. If you add flour or preferably a rue (butter with fkour heated to a high temprature) you can thiken it to a quite thick sauce. If you beat in an egg the heat from the sauce cooks it… Using a microwave you can add eggs one by one and by letting the outside cook through till solid cut it in when you add the next egg. The result is you can make what looks and tastes like soft cooked scrambled eggs with half or less the number of eggs per person.

But when I was effectively bed ridden some time ago due to one of the more anoying maladies I suffer from from time to time. I discovered an interesting thing… I have a very large thermos flask with pump dispenser like you see on tables at conferencez and a smaller thermos jug. If I used the very large thermos as a “tea pot” I could use just one tea bag to make four pints of tea that stayed hot for the day with just one boiling of the kettle in the morning and the small thermos to hold a pint of cold milk. Thus keeping them by the bed kept me hydrated.

Oh and there is a “dirty secret” I was told by someone I know in the catering industry when I was chatting one day and I told them about it the energy saving and it needing just one tea bag. They said “don’t wash it out for the week”… It’s well known in “greasy spoons” / “Dinners and dives” that the practical reality is, it turns out that things “don’t go off” or ferment, if you fill with boiling water once a day. So like those famed tea urns in Russia that are never washed out it just “builds the flavour”…

Also if you use “instant coffee” boil a large kettle of water once a day and pour the boiling water into a large thermos just add enough hot water to disolve the powder and add some cold water to top up to make it a warm drinking temprature.

But it turns out amongst certain older “out doors men” there is an old trick. You have a large flask –non vacuum will do– and last thing at night you fill it with boiling coffee and wrap it in a large cloth or towel. You take this into your sleeping roll as a “hot water bottle” in the morning you have a cup of warm drinkable coffee ready, so you can “get going” immediately then with lighting the fire and starting cooking breakfast etc, you can also warm it through by the fire once lit and drink it till the new coffee is made.

And yes before you ask I’ve tried it with black tea and yes it works OK as well.

Clive Robinson • May 27, 2022 12:16 PM

@ Anonymous,

Also consider where the “root of trust” is and how it is protected.

In effect a properly implemented Smart Card is a “Security Enclave” in it’s own right we might otherwise call a “Hardware Security Module”(HSM).

There are known protocols to use these with “untrusted hardware” and “untrusted software”.

Whilst effectively slow they can raise the level of the game above that of even most sophisticated attackers.

The real question is of course one of trade offs,

1, Smart Cards are quite inexpensive.
2, Trusted terminals are very expensive[1].

So you can guess why they all have Smart Cards.

Now whilst the general type Smart Card is OK for what I identified in my original post, and some user authentication and authorisation it lacks as I noted the facility to be used for transaction authentication and authorisation with Commercial Off The Shelf systems like home PC’s.

So to do “crypto” of messages would require “an independent token” in the chain to move the security end point and subsequent user display device off of the consumer computer.

Which is why I made the point origanally of,

“then the military should not be alowing the use of their systems in this way…”

Even with low level “restricted” or “confidential” material…

[1] You can build your own “hardware cluster” home super-computer for the price of a secure terminal…