Search the forum,

block

In cryptography, a block cipher is a deterministic algorithm operating on fixed-length groups of bits, called blocks. They are specified elementary components in the design of many cryptographic protocols and are widely used to the encryption of large amounts of data, including data exchange protocols. It uses blocks as an unvarying transformation.
Even a secure block cipher is suitable for the encryption of only a single block of data at a time, using a fixed key. A multitude of modes of operation have been designed to allow their repeated use in a secure way to achieve the security goals of confidentiality and authenticity. However, block ciphers may also feature as building blocks in other cryptographic protocols, such as universal hash functions and pseudorandom number generators.

View More On Wikipedia.org
  1. C

    Water pressure for block of flats

    Hi, I will try to explain best I can, please bare in mind I am currently in a learning stage so just trying to understand the process behind things. A building with three floors and 69 rooms. How do you work out the pressure needed on the hot water system? I’m sure there is a calculation to...
  2. R

    Sediment Filter on main supply Block of Flats

    Hi all, I'm on the committee on a community of owners for an apartment complex in Spain. It consists of 130 apartments. We have continual problems of sediment in the incoming water supply, blocking aerator in the taps, filters in shower mixers and even flexible pipes. It's a common problem...
  3. C

    Copper pipes on block and beam

    Hi all. New to this. I Will Try and explain best I can. Large New build (2.5yrs old) with block and beam flooring. Then Membrane Then celotex Then membrane Wet system underfloor heating In approx 2-3” of screed I think Then tiled throughout 15mm Hot and cold copper pipes, felt lagged...
  4. B

    URGENT Leaking PHE inlet block on Heatslave II 25/32

    Heatslave II 25/32 water leak from PHE Inlet block. When DHW PRV fitting was removed a white flat seal/washer was found in 3 pieces. This seal is not listed on any diagram. It sits ahead of the rubber o ring item 45 on drawing and has has the same ID and OD as the oring but is made from white...
  5. B

    Electrical meters in Unit block - With new Plumbing

    hello - I am curious if there is a plumbing standard or electrical standard that applies. Situation is unit block, old 50's apartment - 10+ electrical meters in wire cage together. Someone has put forward a bylaw change that will allow them to run kitchen piping in body corporate areas that will...
  6. M

    Toilet unblocked itself

    I have a weird question. I went into my bathroom and found my partner had put so much toilet paper in the toilet that it was blocked. I tried flushing it and the water filled up almost to the top of the bowl before slowly going back down to a normal level. The flush had completely finished but...
  7. I

    Toilet/shower block pressure problems?

    Where I work we have problem with the hot taps pressure and temperature is quite poor. Apparently it has been poor for a while but was once much better. It is a commercial setting toilet block which is gravity fed from commercial sized tanks. The taps are mixer taps and mixer showers and I...
  8. R

    How to get tap body out of mono block

    Help please! Any ideas how I open this mono block to get to body? I have removed the allen screw but the cap and spindle are still captive and engaged on the the body though they do move in and out about 1/4 inch. I don't want to force anything, have tried a gentle prising on the cap but no joy.
  9. I

    Part to block off dishwasher pipe under sink

    Hi, (Sorry if I'm posting this in the wrong sub-forum - I wasn't sure where to post, so I thought the General Thread would be the safest bet) I'm hoping to get some advice about a part I need to buy. My ex-husband recently took our dishwasher, but when he disconnected it from under the sink...
  10. Tommo25

    Hydro block pin hole worcester

    Went to look at a leaking worcester combi 30cdi, and found it has a pinhole/hairline crack in the flow unit hydro block. (LHS bolts onto plate to plate heat ex) Any tips or anything I should look out for when replacing the flow unit (87161063560) I don't do too much work on Worcester boilers...
  11. M

    Zilmet expansion tank block?

    Brand new 18l Zilmet expansion vessel (red) and the neck seems to be blocked by thick black rubber. Is that the bladder, tank is pressurised but can’t be pushed in with a finger. I just want to check as by the time an engineer comes it’s going to be too late to replace? Matt
  12. A

    How can we block off an unused external boiler flue?

    We had a boiler in an old shed adjacent to the house. The flue is encased in a brick chimney stack that runs up the outside of the house. Some years ago, the boiler was moved inside, but the old flue remains. It looks like a chimney but is open at the bottom and unsightly. I am not sure...
  13. J

    Shut off water on twin inlet H block

    Hi all, Apologies for horrendous terminology and lack of knowledge but I need to remove a vertical radiator which has a H shaped block as shown in the attached image. It seems obvious on my traditional radiators, but on this one I cannot see how to shut off the water to the radiator. Thanks...
  14. C

    Replacement Grohe mono block

    How can i buy an exact replacement as i cannot see how to open the barrel to the hot ceramic disc to replace that? Grohe About 8 years old. Thanks Chris
  15. T

    Communal Shower Block Advice

    We have a communal shower block in our cricket club changing rooms. There are 4 shower heads which each have a mixer valve and are fed by 28mm hot and cold from a header tank and boiler. Water pressure is low due to being miles from anywhere. For years the showers have caused us issues...
  16. Matt0167

    Secondary ecv in an apartment block

    Hi guys can any of you point me to the regs regarding secondary ecv to a flat The flats are 3 storeys high with internal gas rises in a cupboard on the communial landing , This would be perfect for secondary ecv, I know it's meant to be point of entry to the flat but this is just not...
  17. Z

    Newbie on the block :)

    Hi all. So I've registered here to seek a bit of guidance from the seasoned pros :D I've done my cenwat and htr courses recently but been installing gas cooking appliance for a company (around 2 years now). I'm trying to get a job in boiler servicing (then repairs later on) and keep bumping...
  18. S

    flexible mono block tap connector

    Hi, I was just wondering if anyone could help us find a flexible mono block tap connector like the one shown in the picture. It has a female end which is 15mm and the length of it is 450mm. It has a 10mm wide solid pipe on the end which needs to be 100mm long. All our local plumbing suppliers...
  19. F

    New kid on the block

    Hi All, Just joined up so thought I'd drop a note to say hi! Sam
  20. D

    Ideal Standard Mono block tap flexi?

    Hello , Bought a ex display tap and sink the other day and I was wondering what Flexi pipe I need here. I want a compression fitting the other end but what goes at this end. The end with the o-ring is threaded and it copper pipe looks like it pressed into the casting of the tap. If anyone...
Creating content since 2001. Untold Media.

OFFICIAL SPONSORS

OFFICIAL SPONSORS

Back
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website. For the best site experience please disable your AdBlocker.

I've Disabled AdBlock