I had a smoothwall box where the hard disk failed and we didn't notice for 6 months.
I got suspicious when PFY informed me that there hadn't been any updates for it in about 9 month, I checked the website and the other smoothwall box and found a few updates released in that time. Turns out it tried to download the list of available updates to the hard disk and then checked those against the list of updates installed. As it couldn't save the list it found nothing to install!
As it loaded all software into RAM upon boot, and the logging was buffered in memory (and we hadn't needed to check it as it was a backup anyway) everything just kept on running (Firewall rules, VPNs, everything, it just kept on running) until the PFY rebooted it and found it woudn't boot.
I prefer the theory that well developed code is it's own documentation.
I'm a Very strong believer in self documenting code, I simply don't allow my team to create objects, variables, functions, etc that don't tell you what they do.
I'm also a strong believer in adding comments to code. Good, self documenting, code should tell you what it is doing without comments, but often the reason Why it needs to do things are is lost or cannot be conveyed in the code.
tl;dr: Well written code tells you what it does. Well documented code tells you why it does what it does.
All the houses I've lived in in the UK have 1 phase for the entire house and the three phases are used sequentially as you go along the road.
When some but not all of the phases go down and it's night, you can see the effect by looking down the street to see every third house either lit-up or off depending on it being one or two phases that are out.
0.083 cents/kWh for the first 750 kWh, 0.067 cents/kWh thereafter.
0.083 cents? 0.083 cents(US) is about 0.05 pence (Sterling). I pay around 23p (~ 37 cents(US)) for the first 720 kWh per year, then about 9p (~14 cents(US)) for the rest, or around 450 times more than your cost above...
All my prices include VAT, please tell me 0.083 cents is after tax???
28KWh... that's the equivalent of running my generator for 4 hours. Now, my generator produces about twice as much power as we actually need during a power failure (which is why we let the neighbours piggy back their sump pump off it), but if we were running the TV, the computers, the laundry, the air conditioner? There's absolutely no way that a 28KWh battery would provide enough juice to run the place for 2 days. 1 day, if we stretch it, but probably closer to 8 hours of normal daytime household load.
I realise that my case may be atypical, like many geeks I like efficiency so most of our lights are either LED or compact fluorescent lamps. However we use about 8 kW a day in the summer (when not using the washing machine) and about 11 a day in the winter. Washing days push us up to about 12 to 15 kW a day. Weekly consumption is between 55kWh and 70kWh for summer and up to 85+kWh in winter. We would use less but my wife likes light fittings that look nice but require multiple lamps.
This is for a family of 3, and although we have a gas hob we do most of our cooking with a electric grill and oven.
So 28kWh could do us for 2 days, but you wouldn't be driving anywhere afterwards...
Oh, and for the VAST majority of applications gold contacts are a complete waste of money.
Which is something we probably all thought was the case.
This was particularly brought home to me when I discovered that a lot of the Optical Audio cables I've seen recently have suddenly started having gold plated connectors. I mean really, Gold Plating on an Optical cable, does anyone with any intelligence fall for these stupid tricks?
Correct me if I'm wrong but, Yes, what you are saying is true for hashes without salt or systems that allow you to provide an already hashed password (why would you do such a thing?), but for these you do not need the collision the hash itself will do.
In a system that correctly applies the salt, your new input will not generate the same hash. i.e., User sets Password, Password is hashed with the salt (e.g., passwordHash = hash(salt+password) ) You discover the resultant hash, You find a collision that produces the same hash ( hash(collisionValue) == passwordHash ) You then try to use this collisionValue to gain access to the system, but because of the use of a salt the system will take your collisionValue and add the salt, this will produce a completely different resultant hash and will not match the stored password hash.
hash(salt+collisionValue) != passwordHash.
Unless you know of a side-channel attack, or have access to enough hashes where you already know the password in order to determine the salt (or format of the salt for a roaming salt) then your collision is not effective.
Yes you are correct the OP didn't use rainbow tables where salting helps to prevent attacks, but the tables produced were for 1-6 character passwords, without salt. Had he used a 16 character salt (128 extra bits as per bcrypt) then he would not have found a single one of these passwords in that amount of time.
Unless you know the salt and how it is being applied to the password (hash(salt+password), hash(password+salt), hash(hash(password)+salt), etc) you will find it very, very difficult to produce input, not to the hash, but to the authentication system, that can match the resultant password hash.
Let's have a close look at the costs involved when running a Linux system.
Ok, lets have a look...
First off a Linux Install is done in a quarter of the time.
Second All the servers that you may need (with the possible exception of a Exchange Server Replacment) are available for free.
Third backing up does not require that you buy a £300 backup Manager.
An important factor in Linux' cost is its maintenance. Linux requires a *lot* of maintenance,
A Lot? Where did you get this from?
We have several Windows NT/2K servers and they are constantly requiring Maintenance.
Our exchange server had software RAID setup (an oversight from the company we got it from) and suddenly decided that it would spend 88% of both 900MHz CPUs using the disks...
This then cause exchange to die taking the message store with it... 2 days later, with the disks un-RAIDed, re-RAIDed, exchange repaired (only just by the tools supplied) it was running again, but no one knows what caused the computer that had run OK for the 3 months to suddenly die, or what it was that fixed it.
This is the way of microsoft software.
In the same time we got a new hard disk, downloaded Linux (3 CDs), installed, secured, setup accounts, and had a replacment Mail server with LDAP addressbook going with a day to spare...
work doable only by the relatively few high-paid Linux administrators that put themselves - of course willingly - at a great place in the market. Linux seems to be needing maintenance continuously, to keep it from breaking down.
Well all I can say to this is that you either don't know Linux, or are a Windows admin who has tried and failed to learn how to Admin Linux and is bitter about this.
Add to this the cost of loss of data. Linux' native file system, EXT2FS, is known to lose data like a firehose spouts water when the file system isn't unmounted properly.
Windows is no better. Most filesystems are no better. NTFS (Or NT's Fragmented System) just doesn't complain. It's worse if the MFT gets even slightly hurt...
Other unix file systems are much more tolerant towards unexpected crashes. An example is the FreeBSD file system, which with soft updates enabled, performance-wise blows EXT2FS out of the water, and doesn't have the negative drawback of extreme data loss in case of a system breakdown.
Well If you don't think what Linux has is stably enough for you, port the filesystem over and stop complaining...
According to Linux advocates, an alternative to EXT2FS would be ReiserFS. Unfortunately, ReiserFS is still in beta stage. This means it is not intended for production use (although according to many Linux advocates this shouldn't be a problem, which makes me wonder how (little) valuable they find your data).
Others have covered this.
The other proposed 'solution', EXT3FS, is nothing more than an ugly hack to put journaling into the file system. All the drawbacks of the ancient EXT2FS file system remain in EXT3FS,
I, for one, would like to know hat these drawbacks are. My ext2 systems have never failed apart from a hard disk head crash that destroyed a disk and a power surge that also killed a disk.
Funnily enough other opperating systems on thoses disks did not survive either...
for the sake of 'forward- and backward compatibility'. This is interesting, considering that the DOS heritage in the Windows 9x/ME series was considered a very bad thing by the Linux community, even though it provided what could be called one of the best examples of compatibility, ever. When it's about Linux, compatibility constraints don't seem to be that much of a problem for Linux advocates.
Staying with a technology that was old (FAT) and had so many faults (No good disk management, defragmentation, checking, it didn't even notice that it had not been finished writing data when the power was pulled).
Back to Linux' cost.
Hang on I thought this was all about Linux' cost...
Factor in also the fact that crashes happen much more often on Linux than on other unices. On other unices, crashes usually are caused by external sources like power outages. Crashes in Linux are a regular thing, and nobody seems to know what causes them, internally. Linux advocates try to hide this fact by denying crashes ever happen. Instead, they have frequent "hardware problems".
Again no information to back this up. Yes I've crashed Linux. I was running a Kernel I'd hacked up myself. Yes I've crashed X. Keyboard did not respond, mouse died...
I tellneted in from another box and killed X and it all came back.
The steep learning curve compared to about any other operating system out there is a major factor in Linux' cost.
Ah so you're a Windows Admin, that does not understand the way of Unix
The system is a mix of features from all kinds of unices, but not one of them is implemented right. A Linux user has to live with badly coded tools which have low performance, mangle data seemingly at random and are not in line with their specification.
Oh dear, Lost of software is badly coded, not just Linux (OR GNU as it should be called) software. If you dislike it that much you could always rewrite it...
What specification does the other software use? Their own, to make their software 100% compliant because the specification is one the invented to match the product...
Linux software does not mangle data.
Why?
Because if it did it would be fixed within a few hours and you could download it.
On top of that a lot of them spit out the most childish and unprofessional messages, indicating that they were created by 14-year olds with too much time, no talent and a bad attitude.
Go on Name the software that does this.
I could go on and on and on, but the conclusion is clear. Linux is not an option for any one who seeks a professional OS with high performance, scalability, stability, adherence to standards, etc.
The conclusion that we draw is that,
1, You don't know what you're talking about
2, You have nothing to back up these wild claims
3, You Are a troll
In the UK a TV presenter (Roy Castle) died from passive smoking. He had never smoked, but he developed lung cancer from those who had smoked around him
Slashdot Mirror
I had a smoothwall box where the hard disk failed and we didn't notice for 6 months.
I got suspicious when PFY informed me that there hadn't been any updates for it in about 9 month, I checked the website and the other smoothwall box and found a few updates released in that time. Turns out it tried to download the list of available updates to the hard disk and then checked those against the list of updates installed. As it couldn't save the list it found nothing to install!
As it loaded all software into RAM upon boot, and the logging was buffered in memory (and we hadn't needed to check it as it was a backup anyway) everything just kept on running (Firewall rules, VPNs, everything, it just kept on running) until the PFY rebooted it and found it woudn't boot.
SgtWilko.
I prefer the theory that well developed code is it's own documentation.
I'm a Very strong believer in self documenting code, I simply don't allow my team to create objects, variables, functions, etc that don't tell you what they do.
I'm also a strong believer in adding comments to code. Good, self documenting, code should tell you what it is doing without comments, but often the reason Why it needs to do things are is lost or cannot be conveyed in the code.
tl;dr:
Well written code tells you what it does.
Well documented code tells you why it does what it does.
Ahhh, thank goodness for that, three times screwed I can cope with. :-)
At 450 times I was considering running a cable from over there...
Do you have to pay tax on electricity?
All the houses I've lived in in the UK have 1 phase for the entire house and the three phases are used sequentially as you go along the road.
When some but not all of the phases go down and it's night, you can see the effect by looking down the street to see every third house either lit-up or off depending on it being one or two phases that are out.
0.083 cents/kWh for the first 750 kWh, 0.067 cents/kWh thereafter.
0.083 cents?
0.083 cents(US) is about 0.05 pence (Sterling).
I pay around 23p (~ 37 cents(US)) for the first 720 kWh per year, then about 9p (~14 cents(US)) for the rest, or around 450 times more than your cost above...
All my prices include VAT, please tell me 0.083 cents is after tax???
28KWh... that's the equivalent of running my generator for 4 hours. Now, my generator produces about twice as much power as we actually need during a power failure (which is why we let the neighbours piggy back their sump pump off it), but if we were running the TV, the computers, the laundry, the air conditioner? There's absolutely no way that a 28KWh battery would provide enough juice to run the place for 2 days. 1 day, if we stretch it, but probably closer to 8 hours of normal daytime household load.
I realise that my case may be atypical, like many geeks I like efficiency so most of our lights are either LED or compact fluorescent lamps. However we use about 8 kW a day in the summer (when not using the washing machine) and about 11 a day in the winter. Washing days push us up to about 12 to 15 kW a day.
Weekly consumption is between 55kWh and 70kWh for summer and up to 85+kWh in winter.
We would use less but my wife likes light fittings that look nice but require multiple lamps.
This is for a family of 3, and although we have a gas hob we do most of our cooking with a electric grill and oven.
So 28kWh could do us for 2 days, but you wouldn't be driving anywhere afterwards...
Oh, and for the VAST majority of applications gold contacts are a complete waste of money.
Which is something we probably all thought was the case.
This was particularly brought home to me when I discovered that a lot of the Optical Audio cables I've seen recently have suddenly started having gold plated connectors.
I mean really, Gold Plating on an Optical cable, does anyone with any intelligence fall for these stupid tricks?
Correct me if I'm wrong but, Yes, what you are saying is true for hashes without salt or systems that allow you to provide an already hashed password (why would you do such a thing?), but for these you do not need the collision the hash itself will do.
In a system that correctly applies the salt, your new input will not generate the same hash.
i.e.,
User sets Password, Password is hashed with the salt (e.g., passwordHash = hash(salt+password) )
You discover the resultant hash,
You find a collision that produces the same hash ( hash(collisionValue) == passwordHash )
You then try to use this collisionValue to gain access to the system, but because of the use of a salt the system will take your collisionValue and add the salt, this will produce a completely different resultant hash and will not match the stored password hash.
hash(salt+collisionValue) != passwordHash.
Unless you know of a side-channel attack, or have access to enough hashes where you already know the password in order to determine the salt (or format of the salt for a roaming salt) then your collision is not effective.
Yes you are correct the OP didn't use rainbow tables where salting helps to prevent attacks, but the tables produced were for 1-6 character passwords, without salt. Had he used a 16 character salt (128 extra bits as per bcrypt) then he would not have found a single one of these passwords in that amount of time.
Unless you know the salt and how it is being applied to the password (hash(salt+password), hash(password+salt), hash(hash(password)+salt), etc) you will find it very, very difficult to produce input, not to the hash, but to the authentication system, that can match the resultant password hash.
Certainly the BBC page linked to makes no mention of the type of 'plane so I would respectfully suggest that it was a typo of the submitter.
There are other not so over the top CGI's like BlueLava http://www.sgtwilko.f9.co.uk/bluelava
Simple effective and has a web/WAP interface.
Let's have a close look at the costs involved when running a Linux system.
Ok, lets have a look...
First off a Linux Install is done in a quarter of the time.
Second All the servers that you may need (with the possible exception of a Exchange Server Replacment) are available for free.
Third backing up does not require that you buy a £300 backup Manager.
An important factor in Linux' cost is its maintenance. Linux requires a *lot* of maintenance,
A Lot? Where did you get this from? We have several Windows NT/2K servers and they are constantly requiring Maintenance.
Our exchange server had software RAID setup (an oversight from the company we got it from) and suddenly decided that it would spend 88% of both 900MHz CPUs using the disks...
This then cause exchange to die taking the message store with it... 2 days later, with the disks un-RAIDed, re-RAIDed, exchange repaired (only just by the tools supplied) it was running again, but no one knows what caused the computer that had run OK for the 3 months to suddenly die, or what it was that fixed it.
This is the way of microsoft software.
In the same time we got a new hard disk, downloaded Linux (3 CDs), installed, secured, setup accounts, and had a replacment Mail server with LDAP addressbook going with a day to spare...
work doable only by the relatively few high-paid Linux administrators that put themselves - of course willingly - at a great place in the market. Linux seems to be needing maintenance continuously, to keep it from breaking down.
Well all I can say to this is that you either don't know Linux, or are a Windows admin who has tried and failed to learn how to Admin Linux and is bitter about this.
Add to this the cost of loss of data. Linux' native file system, EXT2FS, is known to lose data like a firehose spouts water when the file system isn't unmounted properly.
Windows is no better. Most filesystems are no better. NTFS (Or NT's Fragmented System) just doesn't complain. It's worse if the MFT gets even slightly hurt...
Other unix file systems are much more tolerant towards unexpected crashes. An example is the FreeBSD file system, which with soft updates enabled, performance-wise blows EXT2FS out of the water, and doesn't have the negative drawback of extreme data loss in case of a system breakdown.
Well If you don't think what Linux has is stably enough for you, port the filesystem over and stop complaining...
According to Linux advocates, an alternative to EXT2FS would be ReiserFS. Unfortunately, ReiserFS is still in beta stage. This means it is not intended for production use (although according to many Linux advocates this shouldn't be a problem, which makes me wonder how (little) valuable they find your data).
Others have covered this.
The other proposed 'solution', EXT3FS, is nothing more than an ugly hack to put journaling into the file system. All the drawbacks of the ancient EXT2FS file system remain in EXT3FS,
I, for one, would like to know hat these drawbacks are. My ext2 systems have never failed apart from a hard disk head crash that destroyed a disk and a power surge that also killed a disk.
Funnily enough other opperating systems on thoses disks did not survive either...
for the sake of 'forward- and backward compatibility'. This is interesting, considering that the DOS heritage in the Windows 9x/ME series was considered a very bad thing by the Linux community, even though it provided what could be called one of the best examples of compatibility, ever. When it's about Linux, compatibility constraints don't seem to be that much of a problem for Linux advocates.
Staying with a technology that was old (FAT) and had so many faults (No good disk management, defragmentation, checking, it didn't even notice that it had not been finished writing data when the power was pulled).
Back to Linux' cost.
Hang on I thought this was all about Linux' cost...
Factor in also the fact that crashes happen much more often on Linux than on other unices. On other unices, crashes usually are caused by external sources like power outages. Crashes in Linux are a regular thing, and nobody seems to know what causes them, internally. Linux advocates try to hide this fact by denying crashes ever happen. Instead, they have frequent "hardware problems".
Again no information to back this up. Yes I've crashed Linux. I was running a Kernel I'd hacked up myself. Yes I've crashed X. Keyboard did not respond, mouse died...
I tellneted in from another box and killed X and it all came back.
The steep learning curve compared to about any other operating system out there is a major factor in Linux' cost.
Ah so you're a Windows Admin, that does not understand the way of Unix
The system is a mix of features from all kinds of unices, but not one of them is implemented right. A Linux user has to live with badly coded tools which have low performance, mangle data seemingly at random and are not in line with their specification.
Oh dear, Lost of software is badly coded, not just Linux (OR GNU as it should be called) software. If you dislike it that much you could always rewrite it...
What specification does the other software use?
Their own, to make their software 100% compliant because the specification is one the invented to match the product...
Linux software does not mangle data.
Why?
Because if it did it would be fixed within a few hours and you could download it.
On top of that a lot of them spit out the most childish and unprofessional messages, indicating that they were created by 14-year olds with too much time, no talent and a bad attitude.
Go on Name the software that does this.
I could go on and on and on, but the conclusion is clear. Linux is not an option for any one who seeks a professional OS with high performance, scalability, stability, adherence to standards, etc.
The conclusion that we draw is that,
1, You don't know what you're talking about
2, You have nothing to back up these wild claims
3, You Are a troll
In the UK a TV presenter (Roy Castle) died from passive smoking. He had never smoked, but he developed lung cancer from those who had smoked around him