Visually Differentiable - Bitcoin Addresses
9 messages, 30 Oct 2017. Started by shiva sitamraju.
shiva sitamraju (2), Ben Thompson (2), Ethan Scruples (2), Ricardo Filipe, Pieter Wuille, Danny Thorpe
Hi,
When I copy and paste bitcoin address, I double check the first few bytes, to make sure I copied the correct one. This is to make sure some rogue software is not changing the address, or I incorrectly pasted the wrong address.
With Bech32 address, its seems like in this department we are taking as step in the backward direction. With the traditional address, I could compare first few bytes like 1Ko or 1L3. With bech32, bc1. is all I can see and compare which is likely to be same anyway. Note that most users will only compare the first few bytes only (since addresses themselves are very long and will overflow in a mobile text box).
Is there anyway to make the Bech32 addresses format more visually distinct (atleast the first few bytes) ?
start double checking the last few bytes instead?
2017-10-30 8:56 GMT+00:00 shiva sitamraju via bitcoin-dev <bitcoin-dev@lists•linuxfoundation•org>:
Quoted text (23 lines)
> Hi, > > When I copy and paste bitcoin address, I double check the first few bytes, > to make sure I copied the correct one. This is to make sure some rogue > software is not changing the address, or I incorrectly pasted the wrong > address. > > > With Bech32 address, its seems like in this department we are taking as step > in the backward direction. With the traditional address, I could compare > first few bytes like 1Ko or 1L3. With bech32, bc1. is all I can see and > compare which is likely to be same anyway. Note that most users will only > compare the first few bytes only (since addresses themselves are very long > and will overflow in a mobile text box). > > Is there anyway to make the Bech32 addresses format more visually distinct > (atleast the first few bytes) ? > > _______________________________________________ > bitcoin-dev mailing list > bitcoin-dev@lists•linuxfoundation•org > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev >
Checking the first few bytes of a Bitcoin Address should not be considered sufficient for ensuring that it is correct as it takes less than a second to generate a 3 character vanity address that matches the first 3 characters of an address.
On Mon, 30 Oct 2017, 11:44 shiva sitamraju via bitcoin-dev, < bitcoin-dev@lists•linuxfoundation•org> wrote:
Quoted text (22 lines)
> Hi, > > When I copy and paste bitcoin address, I double check the first few bytes, > to make sure I copied the correct one. This is to make sure some rogue > software is not changing the address, or I incorrectly pasted the wrong > address. > > > With Bech32 address, its seems like in this department we are taking as > step in the backward direction. With the traditional address, I could > compare first few bytes like 1Ko or 1L3. With bech32, bc1. is all I can see > and compare which is likely to be same anyway. Note that most users will > only compare the first few bytes only (since addresses themselves are very > long and will overflow in a mobile text box). > > Is there anyway to make the Bech32 addresses format more visually distinct > (atleast the first few bytes) ? > _______________________________________________ > bitcoin-dev mailing list > bitcoin-dev@lists•linuxfoundation•org > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev >
For example bc1qeklep85ntjz4605drds6aww9u0qr46qzrv5xswd35uhjuj8ahfcqgf6hak in 461e8a4aa0a0e75c06602c505bd7aa06e7116ba5cd98fd6e046e8cbeb00379d6 is 62 bytes ! This is very very long. This will create lot of usability problems in
- Blockexplorers (atleast user should be visually able to compare in a transaction having multiple outputs which one his address) - Mobiles - Payment terminals
From my limited understanding, the purpose of inventing a bitcoin address format is for usability and ease of identification (versus a ECDSA public key), While I get the error/checksum capabilities Bech32 brings, any user would prefer a 20 byte address with a checksum over an address that would wrap several lines !!
On Mon, Oct 30, 2017 at 6:19 PM, Ben Thompson < thompson.benedictjames@gmail•com> wrote:
Quoted text (31 lines)
> Checking the first few bytes of a Bitcoin Address should not be considered > sufficient for ensuring that it is correct as it takes less than a second > to generate a 3 character vanity address that matches the first 3 > characters of an address. > > On Mon, 30 Oct 2017, 11:44 shiva sitamraju via bitcoin-dev, < > bitcoin-dev@lists•linuxfoundation•org> wrote: > >> Hi, >> >> When I copy and paste bitcoin address, I double check the first few >> bytes, to make sure I copied the correct one. This is to make sure some >> rogue software is not changing the address, or I incorrectly pasted the >> wrong address. >> >> >> With Bech32 address, its seems like in this department we are taking as >> step in the backward direction. With the traditional address, I could >> compare first few bytes like 1Ko or 1L3. With bech32, bc1. is all I can see >> and compare which is likely to be same anyway. Note that most users will >> only compare the first few bytes only (since addresses themselves are very >> long and will overflow in a mobile text box). >> >> Is there anyway to make the Bech32 addresses format more visually >> distinct (atleast the first few bytes) ? >> _______________________________________________ >> bitcoin-dev mailing list >> bitcoin-dev@lists•linuxfoundation•org >> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev >> >
The last few bytes can be generated to be the same also.
On Mon, 30 Oct 2017, 14:20 Ricardo Filipe via bitcoin-dev, < bitcoin-dev@lists•linuxfoundation•org> wrote:
Quoted text (36 lines)
> start double checking the last few bytes instead? > > 2017-10-30 8:56 GMT+00:00 shiva sitamraju via bitcoin-dev > <bitcoin-dev@lists•linuxfoundation•org>: > > Hi, > > > > When I copy and paste bitcoin address, I double check the first few > bytes, > > to make sure I copied the correct one. This is to make sure some rogue > > software is not changing the address, or I incorrectly pasted the wrong > > address. > > > > > > With Bech32 address, its seems like in this department we are taking as > step > > in the backward direction. With the traditional address, I could compare > > first few bytes like 1Ko or 1L3. With bech32, bc1. is all I can see and > > compare which is likely to be same anyway. Note that most users will only > > compare the first few bytes only (since addresses themselves are very > long > > and will overflow in a mobile text box). > > > > Is there anyway to make the Bech32 addresses format more visually > distinct > > (atleast the first few bytes) ? > > > > _______________________________________________ > > bitcoin-dev mailing list > > bitcoin-dev@lists•linuxfoundation•org > > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev > > > _______________________________________________ > bitcoin-dev mailing list > bitcoin-dev@lists•linuxfoundation•org > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev >
On Oct 30, 2017 15:21, "shiva sitamraju via bitcoin-dev" < bitcoin-dev@lists•linuxfoundation•org> wrote:
For example bc1qeklep85ntjz4605drds6aww9u0qr46qzrv5xswd35uhjuj8ahfcqgf6hak in 461e8a4aa0a0e75c06602c505bd7aa06e7116ba5cd98fd6e046e8cbeb00379d6 is 62 bytes !
...
While I get the error/checksum capabilities Bech32 brings, any user would prefer a 20 byte address with a checksum over an address that would wrap several lines !!
That's an unfair comparison. You're pasting a P2WSH address which contains a 256-bit hash.
A P2WPKH address (which only contains a 160-bit hash, just like P2PKH and P2SH) in Bech32 is only 42 characters, not 62.
Cheers,
If you are going to rely on human verification of addresses, the best way might be map it to words.
For example, with a 6000 word list, a 25 byte address (with a checksum) could be mapped to 16 words like this:
vocally acquire removed unfounded euphemism sanctuary sectional driving entree freckles aloof vertebrae scribble surround prelaw effort
In my opinion, that is much faster to verify than this:
13gQFTYHuAcfnZjXo2NFsy1E8JGSLwXHCZ
or
bc1qrp33g0q5c5txsp9arysrx4k6zdkfs4nce4xj0gdcccefvpysxf3qccfmv3
Although I really do love Bech32.
On Mon, Oct 30, 2017 at 9:13 AM, shiva sitamraju via bitcoin-dev < bitcoin-dev@lists•linuxfoundation•org> wrote:
Quoted text (58 lines)
> For example bc1qeklep85ntjz4605drds6aww9u0qr46qzrv5xswd35uhjuj8ahfcqgf6hak > in 461e8a4aa0a0e75c06602c505bd7aa06e7116ba5cd98fd6e046e8cbeb00379d6 is 62 > bytes ! This is very very long. This will create lot of usability problems > in > > - Blockexplorers (atleast user should be visually able to compare in a > transaction having multiple outputs which one his address) > - Mobiles > - Payment terminals > > From my limited understanding, the purpose of inventing a bitcoin address > format is for usability and ease of identification (versus a ECDSA public > key), While I get the error/checksum capabilities Bech32 brings, any user > would prefer a 20 byte address with a checksum over an address that would > wrap several lines !! > > > On Mon, Oct 30, 2017 at 6:19 PM, Ben Thompson < > thompson.benedictjames@gmail•com> wrote: > >> Checking the first few bytes of a Bitcoin Address should not be >> considered sufficient for ensuring that it is correct as it takes less than >> a second to generate a 3 character vanity address that matches the first 3 >> characters of an address. >> >> On Mon, 30 Oct 2017, 11:44 shiva sitamraju via bitcoin-dev, < >> bitcoin-dev@lists•linuxfoundation•org> wrote: >> >>> Hi, >>> >>> When I copy and paste bitcoin address, I double check the first few >>> bytes, to make sure I copied the correct one. This is to make sure some >>> rogue software is not changing the address, or I incorrectly pasted the >>> wrong address. >>> >>> >>> With Bech32 address, its seems like in this department we are taking as >>> step in the backward direction. With the traditional address, I could >>> compare first few bytes like 1Ko or 1L3. With bech32, bc1. is all I can see >>> and compare which is likely to be same anyway. Note that most users will >>> only compare the first few bytes only (since addresses themselves are very >>> long and will overflow in a mobile text box). >>> >>> Is there anyway to make the Bech32 addresses format more visually >>> distinct (atleast the first few bytes) ? >>> _______________________________________________ >>> bitcoin-dev mailing list >>> bitcoin-dev@lists•linuxfoundation•org >>> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev >>> >> > > _______________________________________________ > bitcoin-dev mailing list > bitcoin-dev@lists•linuxfoundation•org > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev > >
Humans are very visually oriented, recognizing differences in images more easily than differences in text.
What about generating an image based on the bytes of an address, using something like identicon, used by gravatar? Any small change to the text input produces a significantly different image.
-Danny
On Oct 30, 2017 7:43 AM, "Moral Agent via bitcoin-dev" < bitcoin-dev@lists•linuxfoundation•org> wrote:
Quoted text (89 lines)
> If you are going to rely on human verification of addresses, the best way > might be map it to words. > > For example, with a 6000 word list, a 25 byte address (with a checksum) > could be mapped to 16 words like this: > > vocally acquire removed unfounded > euphemism sanctuary sectional driving > entree freckles aloof vertebrae > scribble surround prelaw effort > > In my opinion, that is much faster to verify than this: > > 13gQFTYHuAcfnZjXo2NFsy1E8JGSLwXHCZ > > or > > bc1qrp33g0q5c5txsp9arysrx4k6zdkfs4nce4xj0gdcccefvpysxf3qccfmv3 > > Although I really do love Bech32. > > On Mon, Oct 30, 2017 at 9:13 AM, shiva sitamraju via bitcoin-dev < > bitcoin-dev@lists•linuxfoundation•org> wrote: > >> For example bc1qeklep85ntjz4605drds6aww9u0qr46qzrv5xswd35uhjuj8ahfcqgf6hak >> in 461e8a4aa0a0e75c06602c505bd7aa06e7116ba5cd98fd6e046e8cbeb00379d6 is >> 62 bytes ! This is very very long. This will create lot of usability >> problems in >> >> - Blockexplorers (atleast user should be visually able to compare in a >> transaction having multiple outputs which one his address) >> - Mobiles >> - Payment terminals >> >> From my limited understanding, the purpose of inventing a bitcoin address >> format is for usability and ease of identification (versus a ECDSA public >> key), While I get the error/checksum capabilities Bech32 brings, any user >> would prefer a 20 byte address with a checksum over an address that would >> wrap several lines !! >> >> >> On Mon, Oct 30, 2017 at 6:19 PM, Ben Thompson < >> thompson.benedictjames@gmail•com> wrote: >> >>> Checking the first few bytes of a Bitcoin Address should not be >>> considered sufficient for ensuring that it is correct as it takes less than >>> a second to generate a 3 character vanity address that matches the first 3 >>> characters of an address. >>> >>> On Mon, 30 Oct 2017, 11:44 shiva sitamraju via bitcoin-dev, < >>> bitcoin-dev@lists•linuxfoundation•org> wrote: >>> >>>> Hi, >>>> >>>> When I copy and paste bitcoin address, I double check the first few >>>> bytes, to make sure I copied the correct one. This is to make sure some >>>> rogue software is not changing the address, or I incorrectly pasted the >>>> wrong address. >>>> >>>> >>>> With Bech32 address, its seems like in this department we are taking as >>>> step in the backward direction. With the traditional address, I could >>>> compare first few bytes like 1Ko or 1L3. With bech32, bc1. is all I can see >>>> and compare which is likely to be same anyway. Note that most users will >>>> only compare the first few bytes only (since addresses themselves are very >>>> long and will overflow in a mobile text box). >>>> >>>> Is there anyway to make the Bech32 addresses format more visually >>>> distinct (atleast the first few bytes) ? >>>> _______________________________________________ >>>> bitcoin-dev mailing list >>>> bitcoin-dev@lists•linuxfoundation•org >>>> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev >>>> >>> >> >> _______________________________________________ >> bitcoin-dev mailing list >> bitcoin-dev@lists•linuxfoundation•org >> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev >> >> > > _______________________________________________ > bitcoin-dev mailing list > bitcoin-dev@lists•linuxfoundation•org > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev > >
Or like keyart: https://pthree.org/2014/04/18/the-drunken-bishop-for-openpgp-keys/
Images would definitely be quicker to verify by a human, but I don't think humans can RELIABLY verify anything close to 25 bytes through an image.
Our visual processing system is designed wrong for this purpose, since it subconsciously "corrects" visual input to whatever we expect to see.
It isn't enough to say that any small change produces a "significantly" different image. What you need is for it to be (practically) impossible to construct an image that looks similar but is wrong, which is a far higher standard. For example, any change to a private key renders a significantly different address -- but it is possible for an attacker to grind their way to a similar-looking address.
I would recommend displaying 16 words in a 4 x 4 grid, but otherwise with no visual distractions.
For example, don't provide an image next to the words as a help. Don't use colors to differentiate two different sets of 16 words. What will happen is people will see a pattern that triggers a sensation of familiarity, and they will not carefully verify all of the words -- which is what security requires.
For higher security keys, you could grind an address with enough zeros at the beginning to be expressed by fewer words. For example, you could grind to an address that could be fully expressed with a 12 word (4 x 3) grid that would be easier for a human to verify reliably.
On Mon, Oct 30, 2017 at 12:15 PM, Danny Thorpe <danny.thorpe@gmail•com> wrote:
Quoted text (101 lines)
> Humans are very visually oriented, recognizing differences in images more > easily than differences in text. > > What about generating an image based on the bytes of an address, using > something like identicon, used by gravatar? Any small change to the text > input produces a significantly different image. > > -Danny > > On Oct 30, 2017 7:43 AM, "Moral Agent via bitcoin-dev" < > bitcoin-dev@lists•linuxfoundation•org> wrote: > >> If you are going to rely on human verification of addresses, the best way >> might be map it to words. >> >> For example, with a 6000 word list, a 25 byte address (with a checksum) >> could be mapped to 16 words like this: >> >> vocally acquire removed unfounded >> euphemism sanctuary sectional driving >> entree freckles aloof vertebrae >> scribble surround prelaw effort >> >> In my opinion, that is much faster to verify than this: >> >> 13gQFTYHuAcfnZjXo2NFsy1E8JGSLwXHCZ >> >> or >> >> bc1qrp33g0q5c5txsp9arysrx4k6zdkfs4nce4xj0gdcccefvpysxf3qccfmv3 >> >> Although I really do love Bech32. >> >> On Mon, Oct 30, 2017 at 9:13 AM, shiva sitamraju via bitcoin-dev < >> bitcoin-dev@lists•linuxfoundation•org> wrote: >> >>> For example bc1qeklep85ntjz4605drds6aww9u0qr46qzrv5xswd35uhjuj8ahfcqgf6hak >>> in 461e8a4aa0a0e75c06602c505bd7aa06e7116ba5cd98fd6e046e8cbeb00379d6 is >>> 62 bytes ! This is very very long. This will create lot of usability >>> problems in >>> >>> - Blockexplorers (atleast user should be visually able to compare in a >>> transaction having multiple outputs which one his address) >>> - Mobiles >>> - Payment terminals >>> >>> From my limited understanding, the purpose of inventing a bitcoin >>> address format is for usability and ease of identification (versus a ECDSA >>> public key), While I get the error/checksum capabilities Bech32 brings, any >>> user would prefer a 20 byte address with a checksum over an address that >>> would wrap several lines !! >>> >>> >>> On Mon, Oct 30, 2017 at 6:19 PM, Ben Thompson < >>> thompson.benedictjames@gmail•com> wrote: >>> >>>> Checking the first few bytes of a Bitcoin Address should not be >>>> considered sufficient for ensuring that it is correct as it takes less than >>>> a second to generate a 3 character vanity address that matches the first 3 >>>> characters of an address. >>>> >>>> On Mon, 30 Oct 2017, 11:44 shiva sitamraju via bitcoin-dev, < >>>> bitcoin-dev@lists•linuxfoundation•org> wrote: >>>> >>>>> Hi, >>>>> >>>>> When I copy and paste bitcoin address, I double check the first few >>>>> bytes, to make sure I copied the correct one. This is to make sure some >>>>> rogue software is not changing the address, or I incorrectly pasted the >>>>> wrong address. >>>>> >>>>> >>>>> With Bech32 address, its seems like in this department we are taking >>>>> as step in the backward direction. With the traditional address, I could >>>>> compare first few bytes like 1Ko or 1L3. With bech32, bc1. is all I can see >>>>> and compare which is likely to be same anyway. Note that most users will >>>>> only compare the first few bytes only (since addresses themselves are very >>>>> long and will overflow in a mobile text box). >>>>> >>>>> Is there anyway to make the Bech32 addresses format more visually >>>>> distinct (atleast the first few bytes) ? >>>>> _______________________________________________ >>>>> bitcoin-dev mailing list >>>>> bitcoin-dev@lists•linuxfoundation•org >>>>> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev >>>>> >>>> >>> >>> _______________________________________________ >>> bitcoin-dev mailing list >>> bitcoin-dev@lists•linuxfoundation•org >>> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev >>> >>> >> >> _______________________________________________ >> bitcoin-dev mailing list >> bitcoin-dev@lists•linuxfoundation•org >> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev >> >>