Verifying a signed message *without* a Bitcoin client installed?

[gweedo]

I've been asked by someone in newbie jail, or unable to register, to post here this online signature verification tool he created: coinig.com.  (Some CYA: this is not an endorsement of the correct functionality, security, privacy, etc. of the tool, just sharing a link.)

Not open source and doesn't use user verifiable javascript to see how the signature is verified. This could be a scam, I know I wouldn't trust it.

[1538088504]

1538088504

[1538088504]

1538088504

[vitruvio]

Congratulations for the good job.

Regards

[jackjack]

I've been asked by someone in newbie jail, or unable to register, to post here this online signature verification tool he created: coinig.com.  (Some CYA: this is not an endorsement of the correct functionality, security, privacy, etc. of the tool, just sharing a link.)

Who's the guy?
Is he currently registered?

[scintill]

Who's the guy?
Is he currently registered?

I was respecting privacy, but on second thought I don't think he would mind.  His name is Gregor Volkmann and his site is at http://gregor.volkmann.me/ .  He contacted me by email so I don't have a username, and I couldn't find one with search.  I haven't heard from him since telling him I posted, so I guess he hasn't registered.  He probably only would have posted the link, but looking at his home page he seems open to being contacted, if people have questions or whatnot.

[the_beast]

Maybe it's one more tool for handling signatures, but you could try FSV. This is a new multiple-platform GUI soft for PC. It's a pretty handy tool for signed messages checking.

https://bitcointalk.org/index.php?topic=623085.msg6904979#msg6904979

[gweedo]

If anyone wants apicoin can do many verifications of signatures at once, https://apicoin.io/api/v1/doc/#verifymessage

[jonald_fyookball]

is this done in PHP?

if not, i can do it, is there a bounty?

[UserVVIP]

It should be pretty easy to do either way.

[rjmacarthy]

I'd use bitcore.io to do this.

http://bitcore.io/api/transaction/transaction.html#Transaction#verifySignature

Javascript framework can be installed locally or using node.js.

Hope this helps.

[BitTalkyy]

Check my tutorial with PHP here -> https://bitcointalk.org/index.php?topic=1210197.0

[bit22gen]

If I have a Bitcoin address and a message signed with the private key of that address, is there a way to verify the signature with standard Unix commands?

bitsig (C++) can verify signatures:

http://bitcoin-gen.org/

Example:

$ bitsig verifyRaw "test" G93M44UVAiOAe7do7TJbtFrvedSpjoq6HFzCT0KZZW07/TvpE/qXxiZf6q7OV4nIqYkq9DDYPbvYTemsmpb0kbk= 17RjaCGZQbe2Cw984YdWcMcWDgM86kM7EN
Verifying raw message: test
Verifying signature...
Signed by the address: 17RjaCGZQbe2Cw984YdWcMcWDgM86kM7EN