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Title: who can explain how signing/verifing message works? Post by: newcn on December 13, 2013, 11:24:20 AM Using a bitcoin client, one can sign/verify messages.
I understand that I use my private key to sign a message, but I wonder why other people can verify messages which I signed? since the key is private, and other people don't know. Title: Re: who can explain how signing/verifing message works? Post by: Aeequtio on December 15, 2013, 06:01:14 AM I would like to know more about that as well.
Can anyone shed some light on it? Title: Re: who can explain how signing/verifing message works? Post by: binaryclock on December 15, 2013, 06:44:50 AM Me 3, plz
Title: Re: who can explain how signing/verifing message works? Post by: shorena on December 15, 2013, 06:58:17 AM The verfication is done with your public key.
Basicly its a o = m^d (mod N) where o is the signature, m is the message and d is the private key Because RSA has some vulnerabilites, the message gets hashed first. To check the signature you calulate o^e = m (mod N) where e is the public key to the former used private key. If the hashes match the message wasnt changed durring transport. This works because ed = 1 (mod phi(N)) while e and N again are part of the public key and d is the private key If you want more details, read the rfc 3447, its explained for RSA, but the principle is still the same Link: http://tools.ietf.org/html/rfc3447#page-27 Edit: phi(x) is eulers phi function ( http://en.wikipedia.org/wiki/Euler%27s_totient_function ) Title: Re: who can explain how signing/verifing message works? Post by: newcn on January 04, 2014, 12:41:30 PM The verfication is done with your public key. Basicly its a o = m^d (mod N) where o is the signature, m is the message and d is the private key Because RSA has some vulnerabilites, the message gets hashed first. To check the signature you calulate o^e = m (mod N) where e is the public key to the former used private key. If the hashes match the message wasnt changed durring transport. This works because ed = 1 (mod phi(N)) while e and N again are part of the public key and d is the private key If you want more details, read the rfc 3447, its explained for RSA, but the principle is still the same Link: http://tools.ietf.org/html/rfc3447#page-27 Edit: phi(x) is eulers phi function ( http://en.wikipedia.org/wiki/Euler%27s_totient_function ) thank you very much! |