What does “in-house hash function” mean?
up vote
10
down vote
favorite
In security news, I faced a new term related to hash functions: it is reported that the "in-house hash function" used in IOTA platform is broken (i.e. Curl-P hash function). You can find the complete paper introducing the vulnerability here.
But I do not understand if the term of "in-house" represents a specific type of hash function? And in general, what does "in-house" mean here?
hash terminology
edited 12 hours ago
Anders
48.2k22136157
asked 15 hours ago
sas
394128
add a comment |
up vote
10
down vote
favorite
In security news, I faced a new term related to hash functions: it is reported that the "in-house hash function" used in IOTA platform is broken (i.e. Curl-P hash function). You can find the complete paper introducing the vulnerability here.
But I do not understand if the term of "in-house" represents a specific type of hash function? And in general, what does "in-house" mean here?
hash terminology
edited 12 hours ago
Anders
48.2k22136157
asked 15 hours ago
sas
394128
27
I believe the definition of "In-house hash function" is "Don't use our product, we have no idea what we're doing". (see Steffen's answer for a less cheeky response)
– Mike Ounsworth
15 hours ago
8
It means the same thing that "homeowner wiring" means to electricians.
– Eric Lippert
8 hours ago
4
@EricLippert Be fair. There's less of a chance of a catastrophic fire and loss of life with homeowner wiring.
– Nic Hartley
7 hours ago
add a comment |
up vote
10
down vote
favorite
up vote
10
down vote
favorite
In security news, I faced a new term related to hash functions: it is reported that the "in-house hash function" used in IOTA platform is broken (i.e. Curl-P hash function). You can find the complete paper introducing the vulnerability here.
But I do not understand if the term of "in-house" represents a specific type of hash function? And in general, what does "in-house" mean here?
hash terminology
edited 12 hours ago
Anders
48.2k22136157
asked 15 hours ago
sas
394128
In security news, I faced a new term related to hash functions: it is reported that the "in-house hash function" used in IOTA platform is broken (i.e. Curl-P hash function). You can find the complete paper introducing the vulnerability here.
But I do not understand if the term of "in-house" represents a specific type of hash function? And in general, what does "in-house" mean here?
hash terminology
hash terminology
edited 12 hours ago
Anders
48.2k22136157
asked 15 hours ago
sas
394128
edited 12 hours ago
Anders
48.2k22136157
asked 15 hours ago
sas
394128
edited 12 hours ago
Anders
48.2k22136157
edited 12 hours ago
Anders
48.2k22136157
edited 12 hours ago
Anders
48.2k22136157
48.2k22136157
asked 15 hours ago
sas
394128
asked 15 hours ago
sas
394128
asked 15 hours ago
sas
394128
394128
27
I believe the definition of "In-house hash function" is "Don't use our product, we have no idea what we're doing". (see Steffen's answer for a less cheeky response)
– Mike Ounsworth
15 hours ago
8
It means the same thing that "homeowner wiring" means to electricians.
– Eric Lippert
8 hours ago
4
@EricLippert Be fair. There's less of a chance of a catastrophic fire and loss of life with homeowner wiring.
– Nic Hartley
7 hours ago
add a comment |
27
I believe the definition of "In-house hash function" is "Don't use our product, we have no idea what we're doing". (see Steffen's answer for a less cheeky response)
– Mike Ounsworth
15 hours ago
8
It means the same thing that "homeowner wiring" means to electricians.
– Eric Lippert
8 hours ago
4
@EricLippert Be fair. There's less of a chance of a catastrophic fire and loss of life with homeowner wiring.
– Nic Hartley
7 hours ago
27
27
I believe the definition of "In-house hash function" is "Don't use our product, we have no idea what we're doing". (see Steffen's answer for a less cheeky response)
– Mike Ounsworth
15 hours ago
I believe the definition of "In-house hash function" is "Don't use our product, we have no idea what we're doing". (see Steffen's answer for a less cheeky response)
– Mike Ounsworth
15 hours ago
8
8
It means the same thing that "homeowner wiring" means to electricians.
– Eric Lippert
8 hours ago
It means the same thing that "homeowner wiring" means to electricians.
– Eric Lippert
8 hours ago
4
4
@EricLippert Be fair. There's less of a chance of a catastrophic fire and loss of life with homeowner wiring.
– Nic Hartley
7 hours ago
@EricLippert Be fair. There's less of a chance of a catastrophic fire and loss of life with homeowner wiring.
– Nic Hartley
7 hours ago
add a comment |
2 Answers
2
active
oldest
votes
up vote
43
down vote
accepted
From the explanation of in-house in the Cambridge Directory: "Something that is done in-house is done within an organization or business by its employees rather than by other people".
Here it means developing your own hash algorithm instead of using a public one. Usually that means that it is developed by only a few people with only limited expertise in the problem area and without any public input. Thus it is very likely that the self-developed one gets eventually broken once more experts in cryptography take a look at it.
See also Why shouldn't we roll our own? and How valuable is secrecy of an algorithm?.
answered 15 hours ago
Steffen Ullrich
111k12195258
27
Hearing "in-house" with anything security related is always a HUGE red flag.
– Marie
12 hours ago
1
And hearing "in-house" with anything crypto related is an even larger red flag even more often.
– NieDzejkob
7 hours ago
Also see Is my developer's home-brew password security right or wrong, and why?, although I suspect Dave's algorithm was much, much worse than IOTA's.
– jpmc26
7 hours ago
add a comment |
up vote
-6
down vote
I agree with the answer given an hour before this one about in-house meaning, "non-standard and probably not very sophisticated or rugged." There may still be one argument in favor of using an in-house hash. That is, it may be different enough from the standard ones out there that a hacker may decide it is too much work to figure out how to reverse engineer it. Even if you accept this argument, this sort of do-it-yourself approach should only ever be used to protect very low-value data.
answered 11 hours ago
Peter Knibbe
1
New contributor
Peter Knibbe is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
8
This line of reasoning - relying on an attacker not knowing the implementation details and hoping that they won't find out - is named "Security by Obscurity". Since this is only a slowdown, rarely really a barrier, it is generally frowned upon and strongly recommended against. One area where it still does make sense is if your assets drop rapidly in worth in a short time (days to months) and an attack after one year is much less of an impact. Most game and movie DRM / copy protection schemes fall under this category.
– Zefiro
11 hours ago
3
It's almost a trope at this point that whenever a "why is X bad?" question is posted, there will be an answer that says, paraphrasing, "well it's not that bad, because at least the attackers won't know how your version works". In other words, an appeal to Security by Obscurity. And yes, I get that this answer doesn't reject the premise, but others have done.
– Tom W
10 hours ago
@Zefiro: There is a difference between "hoping that an attacker doesn't find out", and considering the cost/benefit ratios for possible attacks. To be sure, the risk of a popular encryption or hashing scheme being defeated may be slight, despite the level of research into attacks on them, but the probability of a scheme no prospective attackers would care about being defeated might be even lower.
– supercat
9 hours ago
@Zefiro This reasoning is not about an attacker not knowing the implementation details. I think you need to read it again. It's about an attacker not having sufficient motivation to bother trying to break the algorithm. (It's still wrong, but not because it's security by obscurity, because it's not security at all. The problem is that you're very likely to drastically overestimate how much security you actually have, and that's exactly what happened here.)
– David Schwartz
9 hours ago
2
@supercat The problem is that normally, it's just security by obscurity. If you, say, shuffle an otherwise secure hash before storing (and unshuffle on retrieval and comparison), sure, that does extremely little for security, but it doesn't harm it. If all that's done is the shuffle, that's... very bad. And it's the latter case that's normally done, not the former. So people say "don't ever use it", because that's a good rule of thumb, and once you're experienced enough to know the difference, you're experienced enough to know when to ignore rules of thumb.
– Nic Hartley
7 hours ago
|
show 2 more comments
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
43
down vote
accepted
From the explanation of in-house in the Cambridge Directory: "Something that is done in-house is done within an organization or business by its employees rather than by other people".
Here it means developing your own hash algorithm instead of using a public one. Usually that means that it is developed by only a few people with only limited expertise in the problem area and without any public input. Thus it is very likely that the self-developed one gets eventually broken once more experts in cryptography take a look at it.
See also Why shouldn't we roll our own? and How valuable is secrecy of an algorithm?.
answered 15 hours ago
Steffen Ullrich
111k12195258
27
Hearing "in-house" with anything security related is always a HUGE red flag.
– Marie
12 hours ago
1
And hearing "in-house" with anything crypto related is an even larger red flag even more often.
– NieDzejkob
7 hours ago
Also see Is my developer's home-brew password security right or wrong, and why?, although I suspect Dave's algorithm was much, much worse than IOTA's.
– jpmc26
7 hours ago
add a comment |
up vote
43
down vote
accepted
From the explanation of in-house in the Cambridge Directory: "Something that is done in-house is done within an organization or business by its employees rather than by other people".
Here it means developing your own hash algorithm instead of using a public one. Usually that means that it is developed by only a few people with only limited expertise in the problem area and without any public input. Thus it is very likely that the self-developed one gets eventually broken once more experts in cryptography take a look at it.
See also Why shouldn't we roll our own? and How valuable is secrecy of an algorithm?.
answered 15 hours ago
Steffen Ullrich
111k12195258
27
Hearing "in-house" with anything security related is always a HUGE red flag.
– Marie
12 hours ago
1
And hearing "in-house" with anything crypto related is an even larger red flag even more often.
– NieDzejkob
7 hours ago
Also see Is my developer's home-brew password security right or wrong, and why?, although I suspect Dave's algorithm was much, much worse than IOTA's.
– jpmc26
7 hours ago
add a comment |
up vote
43
down vote
accepted
up vote
43
down vote
accepted
From the explanation of in-house in the Cambridge Directory: "Something that is done in-house is done within an organization or business by its employees rather than by other people".
Here it means developing your own hash algorithm instead of using a public one. Usually that means that it is developed by only a few people with only limited expertise in the problem area and without any public input. Thus it is very likely that the self-developed one gets eventually broken once more experts in cryptography take a look at it.
See also Why shouldn't we roll our own? and How valuable is secrecy of an algorithm?.
answered 15 hours ago
Steffen Ullrich
111k12195258
From the explanation of in-house in the Cambridge Directory: "Something that is done in-house is done within an organization or business by its employees rather than by other people".
Here it means developing your own hash algorithm instead of using a public one. Usually that means that it is developed by only a few people with only limited expertise in the problem area and without any public input. Thus it is very likely that the self-developed one gets eventually broken once more experts in cryptography take a look at it.
See also Why shouldn't we roll our own? and How valuable is secrecy of an algorithm?.
answered 15 hours ago
Steffen Ullrich
111k12195258
edited 12 hours ago
answered 15 hours ago
Steffen Ullrich
111k12195258
answered 15 hours ago
Steffen Ullrich
111k12195258
answered 15 hours ago
Steffen Ullrich
111k12195258
111k12195258
27
Hearing "in-house" with anything security related is always a HUGE red flag.
– Marie
12 hours ago
1
And hearing "in-house" with anything crypto related is an even larger red flag even more often.
– NieDzejkob
7 hours ago
Also see Is my developer's home-brew password security right or wrong, and why?, although I suspect Dave's algorithm was much, much worse than IOTA's.
– jpmc26
7 hours ago
add a comment |
27
Hearing "in-house" with anything security related is always a HUGE red flag.
– Marie
12 hours ago
1
And hearing "in-house" with anything crypto related is an even larger red flag even more often.
– NieDzejkob
7 hours ago
Also see Is my developer's home-brew password security right or wrong, and why?, although I suspect Dave's algorithm was much, much worse than IOTA's.
– jpmc26
7 hours ago
27
27
Hearing "in-house" with anything security related is always a HUGE red flag.
– Marie
12 hours ago
Hearing "in-house" with anything security related is always a HUGE red flag.
– Marie
12 hours ago
1
1
And hearing "in-house" with anything crypto related is an even larger red flag even more often.
– NieDzejkob
7 hours ago
And hearing "in-house" with anything crypto related is an even larger red flag even more often.
– NieDzejkob
7 hours ago
Also see Is my developer's home-brew password security right or wrong, and why?, although I suspect Dave's algorithm was much, much worse than IOTA's.
– jpmc26
7 hours ago
Also see Is my developer's home-brew password security right or wrong, and why?, although I suspect Dave's algorithm was much, much worse than IOTA's.
– jpmc26
7 hours ago
add a comment |
up vote
-6
down vote
I agree with the answer given an hour before this one about in-house meaning, "non-standard and probably not very sophisticated or rugged." There may still be one argument in favor of using an in-house hash. That is, it may be different enough from the standard ones out there that a hacker may decide it is too much work to figure out how to reverse engineer it. Even if you accept this argument, this sort of do-it-yourself approach should only ever be used to protect very low-value data.
answered 11 hours ago
Peter Knibbe
1
New contributor
Peter Knibbe is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
8
This line of reasoning - relying on an attacker not knowing the implementation details and hoping that they won't find out - is named "Security by Obscurity". Since this is only a slowdown, rarely really a barrier, it is generally frowned upon and strongly recommended against. One area where it still does make sense is if your assets drop rapidly in worth in a short time (days to months) and an attack after one year is much less of an impact. Most game and movie DRM / copy protection schemes fall under this category.
– Zefiro
11 hours ago
3
It's almost a trope at this point that whenever a "why is X bad?" question is posted, there will be an answer that says, paraphrasing, "well it's not that bad, because at least the attackers won't know how your version works". In other words, an appeal to Security by Obscurity. And yes, I get that this answer doesn't reject the premise, but others have done.
– Tom W
10 hours ago
@Zefiro: There is a difference between "hoping that an attacker doesn't find out", and considering the cost/benefit ratios for possible attacks. To be sure, the risk of a popular encryption or hashing scheme being defeated may be slight, despite the level of research into attacks on them, but the probability of a scheme no prospective attackers would care about being defeated might be even lower.
– supercat
9 hours ago
@Zefiro This reasoning is not about an attacker not knowing the implementation details. I think you need to read it again. It's about an attacker not having sufficient motivation to bother trying to break the algorithm. (It's still wrong, but not because it's security by obscurity, because it's not security at all. The problem is that you're very likely to drastically overestimate how much security you actually have, and that's exactly what happened here.)
– David Schwartz
9 hours ago
2
@supercat The problem is that normally, it's just security by obscurity. If you, say, shuffle an otherwise secure hash before storing (and unshuffle on retrieval and comparison), sure, that does extremely little for security, but it doesn't harm it. If all that's done is the shuffle, that's... very bad. And it's the latter case that's normally done, not the former. So people say "don't ever use it", because that's a good rule of thumb, and once you're experienced enough to know the difference, you're experienced enough to know when to ignore rules of thumb.
– Nic Hartley
7 hours ago
|
show 2 more comments
up vote
-6
down vote
I agree with the answer given an hour before this one about in-house meaning, "non-standard and probably not very sophisticated or rugged." There may still be one argument in favor of using an in-house hash. That is, it may be different enough from the standard ones out there that a hacker may decide it is too much work to figure out how to reverse engineer it. Even if you accept this argument, this sort of do-it-yourself approach should only ever be used to protect very low-value data.
answered 11 hours ago
Peter Knibbe
1
New contributor
Peter Knibbe is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
8
This line of reasoning - relying on an attacker not knowing the implementation details and hoping that they won't find out - is named "Security by Obscurity". Since this is only a slowdown, rarely really a barrier, it is generally frowned upon and strongly recommended against. One area where it still does make sense is if your assets drop rapidly in worth in a short time (days to months) and an attack after one year is much less of an impact. Most game and movie DRM / copy protection schemes fall under this category.
– Zefiro
11 hours ago
3
It's almost a trope at this point that whenever a "why is X bad?" question is posted, there will be an answer that says, paraphrasing, "well it's not that bad, because at least the attackers won't know how your version works". In other words, an appeal to Security by Obscurity. And yes, I get that this answer doesn't reject the premise, but others have done.
– Tom W
10 hours ago
@Zefiro: There is a difference between "hoping that an attacker doesn't find out", and considering the cost/benefit ratios for possible attacks. To be sure, the risk of a popular encryption or hashing scheme being defeated may be slight, despite the level of research into attacks on them, but the probability of a scheme no prospective attackers would care about being defeated might be even lower.
– supercat
9 hours ago
@Zefiro This reasoning is not about an attacker not knowing the implementation details. I think you need to read it again. It's about an attacker not having sufficient motivation to bother trying to break the algorithm. (It's still wrong, but not because it's security by obscurity, because it's not security at all. The problem is that you're very likely to drastically overestimate how much security you actually have, and that's exactly what happened here.)
– David Schwartz
9 hours ago
2
@supercat The problem is that normally, it's just security by obscurity. If you, say, shuffle an otherwise secure hash before storing (and unshuffle on retrieval and comparison), sure, that does extremely little for security, but it doesn't harm it. If all that's done is the shuffle, that's... very bad. And it's the latter case that's normally done, not the former. So people say "don't ever use it", because that's a good rule of thumb, and once you're experienced enough to know the difference, you're experienced enough to know when to ignore rules of thumb.
– Nic Hartley
7 hours ago
|
show 2 more comments
up vote
-6
down vote
up vote
-6
down vote
I agree with the answer given an hour before this one about in-house meaning, "non-standard and probably not very sophisticated or rugged." There may still be one argument in favor of using an in-house hash. That is, it may be different enough from the standard ones out there that a hacker may decide it is too much work to figure out how to reverse engineer it. Even if you accept this argument, this sort of do-it-yourself approach should only ever be used to protect very low-value data.
answered 11 hours ago
Peter Knibbe
1
New contributor
Peter Knibbe is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
I agree with the answer given an hour before this one about in-house meaning, "non-standard and probably not very sophisticated or rugged." There may still be one argument in favor of using an in-house hash. That is, it may be different enough from the standard ones out there that a hacker may decide it is too much work to figure out how to reverse engineer it. Even if you accept this argument, this sort of do-it-yourself approach should only ever be used to protect very low-value data.
answered 11 hours ago
Peter Knibbe
1
New contributor
Peter Knibbe is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
answered 11 hours ago
Peter Knibbe
1
New contributor
Peter Knibbe is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
answered 11 hours ago
Peter Knibbe
1
answered 11 hours ago
Peter Knibbe
1
1
New contributor
Peter Knibbe is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
Peter Knibbe is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
Peter Knibbe is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
8
This line of reasoning - relying on an attacker not knowing the implementation details and hoping that they won't find out - is named "Security by Obscurity". Since this is only a slowdown, rarely really a barrier, it is generally frowned upon and strongly recommended against. One area where it still does make sense is if your assets drop rapidly in worth in a short time (days to months) and an attack after one year is much less of an impact. Most game and movie DRM / copy protection schemes fall under this category.
– Zefiro
11 hours ago
3
It's almost a trope at this point that whenever a "why is X bad?" question is posted, there will be an answer that says, paraphrasing, "well it's not that bad, because at least the attackers won't know how your version works". In other words, an appeal to Security by Obscurity. And yes, I get that this answer doesn't reject the premise, but others have done.
– Tom W
10 hours ago
@Zefiro: There is a difference between "hoping that an attacker doesn't find out", and considering the cost/benefit ratios for possible attacks. To be sure, the risk of a popular encryption or hashing scheme being defeated may be slight, despite the level of research into attacks on them, but the probability of a scheme no prospective attackers would care about being defeated might be even lower.
– supercat
9 hours ago
@Zefiro This reasoning is not about an attacker not knowing the implementation details. I think you need to read it again. It's about an attacker not having sufficient motivation to bother trying to break the algorithm. (It's still wrong, but not because it's security by obscurity, because it's not security at all. The problem is that you're very likely to drastically overestimate how much security you actually have, and that's exactly what happened here.)
– David Schwartz
9 hours ago
2
@supercat The problem is that normally, it's just security by obscurity. If you, say, shuffle an otherwise secure hash before storing (and unshuffle on retrieval and comparison), sure, that does extremely little for security, but it doesn't harm it. If all that's done is the shuffle, that's... very bad. And it's the latter case that's normally done, not the former. So people say "don't ever use it", because that's a good rule of thumb, and once you're experienced enough to know the difference, you're experienced enough to know when to ignore rules of thumb.
– Nic Hartley
7 hours ago
|
show 2 more comments
8
This line of reasoning - relying on an attacker not knowing the implementation details and hoping that they won't find out - is named "Security by Obscurity". Since this is only a slowdown, rarely really a barrier, it is generally frowned upon and strongly recommended against. One area where it still does make sense is if your assets drop rapidly in worth in a short time (days to months) and an attack after one year is much less of an impact. Most game and movie DRM / copy protection schemes fall under this category.
– Zefiro
11 hours ago
3
It's almost a trope at this point that whenever a "why is X bad?" question is posted, there will be an answer that says, paraphrasing, "well it's not that bad, because at least the attackers won't know how your version works". In other words, an appeal to Security by Obscurity. And yes, I get that this answer doesn't reject the premise, but others have done.
– Tom W
10 hours ago
@Zefiro: There is a difference between "hoping that an attacker doesn't find out", and considering the cost/benefit ratios for possible attacks. To be sure, the risk of a popular encryption or hashing scheme being defeated may be slight, despite the level of research into attacks on them, but the probability of a scheme no prospective attackers would care about being defeated might be even lower.
– supercat
9 hours ago
@Zefiro This reasoning is not about an attacker not knowing the implementation details. I think you need to read it again. It's about an attacker not having sufficient motivation to bother trying to break the algorithm. (It's still wrong, but not because it's security by obscurity, because it's not security at all. The problem is that you're very likely to drastically overestimate how much security you actually have, and that's exactly what happened here.)
– David Schwartz
9 hours ago
2
@supercat The problem is that normally, it's just security by obscurity. If you, say, shuffle an otherwise secure hash before storing (and unshuffle on retrieval and comparison), sure, that does extremely little for security, but it doesn't harm it. If all that's done is the shuffle, that's... very bad. And it's the latter case that's normally done, not the former. So people say "don't ever use it", because that's a good rule of thumb, and once you're experienced enough to know the difference, you're experienced enough to know when to ignore rules of thumb.
– Nic Hartley
7 hours ago
8
8
This line of reasoning - relying on an attacker not knowing the implementation details and hoping that they won't find out - is named "Security by Obscurity". Since this is only a slowdown, rarely really a barrier, it is generally frowned upon and strongly recommended against. One area where it still does make sense is if your assets drop rapidly in worth in a short time (days to months) and an attack after one year is much less of an impact. Most game and movie DRM / copy protection schemes fall under this category.
– Zefiro
11 hours ago
This line of reasoning - relying on an attacker not knowing the implementation details and hoping that they won't find out - is named "Security by Obscurity". Since this is only a slowdown, rarely really a barrier, it is generally frowned upon and strongly recommended against. One area where it still does make sense is if your assets drop rapidly in worth in a short time (days to months) and an attack after one year is much less of an impact. Most game and movie DRM / copy protection schemes fall under this category.
– Zefiro
11 hours ago
3
3
It's almost a trope at this point that whenever a "why is X bad?" question is posted, there will be an answer that says, paraphrasing, "well it's not that bad, because at least the attackers won't know how your version works". In other words, an appeal to Security by Obscurity. And yes, I get that this answer doesn't reject the premise, but others have done.
– Tom W
10 hours ago
It's almost a trope at this point that whenever a "why is X bad?" question is posted, there will be an answer that says, paraphrasing, "well it's not that bad, because at least the attackers won't know how your version works". In other words, an appeal to Security by Obscurity. And yes, I get that this answer doesn't reject the premise, but others have done.
– Tom W
10 hours ago
@Zefiro: There is a difference between "hoping that an attacker doesn't find out", and considering the cost/benefit ratios for possible attacks. To be sure, the risk of a popular encryption or hashing scheme being defeated may be slight, despite the level of research into attacks on them, but the probability of a scheme no prospective attackers would care about being defeated might be even lower.
– supercat
9 hours ago
@Zefiro: There is a difference between "hoping that an attacker doesn't find out", and considering the cost/benefit ratios for possible attacks. To be sure, the risk of a popular encryption or hashing scheme being defeated may be slight, despite the level of research into attacks on them, but the probability of a scheme no prospective attackers would care about being defeated might be even lower.
– supercat
9 hours ago
@Zefiro This reasoning is not about an attacker not knowing the implementation details. I think you need to read it again. It's about an attacker not having sufficient motivation to bother trying to break the algorithm. (It's still wrong, but not because it's security by obscurity, because it's not security at all. The problem is that you're very likely to drastically overestimate how much security you actually have, and that's exactly what happened here.)
– David Schwartz
9 hours ago
@Zefiro This reasoning is not about an attacker not knowing the implementation details. I think you need to read it again. It's about an attacker not having sufficient motivation to bother trying to break the algorithm. (It's still wrong, but not because it's security by obscurity, because it's not security at all. The problem is that you're very likely to drastically overestimate how much security you actually have, and that's exactly what happened here.)
– David Schwartz
9 hours ago
2
2
@supercat The problem is that normally, it's just security by obscurity. If you, say, shuffle an otherwise secure hash before storing (and unshuffle on retrieval and comparison), sure, that does extremely little for security, but it doesn't harm it. If all that's done is the shuffle, that's... very bad. And it's the latter case that's normally done, not the former. So people say "don't ever use it", because that's a good rule of thumb, and once you're experienced enough to know the difference, you're experienced enough to know when to ignore rules of thumb.
– Nic Hartley
7 hours ago
@supercat The problem is that normally, it's just security by obscurity. If you, say, shuffle an otherwise secure hash before storing (and unshuffle on retrieval and comparison), sure, that does extremely little for security, but it doesn't harm it. If all that's done is the shuffle, that's... very bad. And it's the latter case that's normally done, not the former. So people say "don't ever use it", because that's a good rule of thumb, and once you're experienced enough to know the difference, you're experienced enough to know when to ignore rules of thumb.
– Nic Hartley
7 hours ago
|
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27
I believe the definition of "In-house hash function" is "Don't use our product, we have no idea what we're doing". (see Steffen's answer for a less cheeky response)
– Mike Ounsworth
15 hours ago
8
It means the same thing that "homeowner wiring" means to electricians.
– Eric Lippert
8 hours ago
4
@EricLippert Be fair. There's less of a chance of a catastrophic fire and loss of life with homeowner wiring.
– Nic Hartley
7 hours ago