In cryptography a blind signature, as introduced by David Chaum, is a form of digital signature .. “Blind signatures for untraceable payments” (PDF). Advances in. Chaum, D. () Blind Signatures for Untraceable Payments. In Chaum, D., Rivest R.L. and Sherman, A.T., Eds., Advances in Cryptology Proceedings of. Semantic Scholar extracted view of “Blind Signatures for Untraceable Payments” by David Chaum.
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Blind signature schemes see a great deal of use in applications where sender privacy is important. Alice can then open it to find the letter signed by Bob, but without Bob having seen its contents. When the attacker removes the blindness the signed version they will have the clear text:.
Blind signatures can also be used to provide unlinkabilitywhich prevents the signer from linking the blinded message it signs to a later un-blinded version that it may be called upon to verify. RSA is subject to the RSA blinding attack through which it is possible to be tricked into decrypting a message by blind signing another message.
This property does not hold for the simple scheme described above: In some blind signature schemes, such as RSA, it is even possible to remove the blinding factor from the signature before it is verified. Blind signature schemes exist for many public key signing protocols. Potential problems are analyzed and solutions offered. This is similar to the way zero-knowledge is defined in zero-knowledge proof systems.
The signing authority then calculates the blinded signature s’ as:. In each example, the message to be signed is contained in the value m.
Once signed, the package is untracsable back to the voter, who transfers the now signed ballot to a new unmarked normal envelope. The message is now easily obtained. In practice, the property that signing one blinded message produces at most one valid signed messages is usually desired.
The author of the message computes the product of the message and blinding factor, i. We consider the development of Bitcoin and its sister currencies as an important disruptive financial innovation which is here to stay unless throttled by ill-considered legislative or regulatory actions.
Are Disruptive Financial Innovations Here? Thus, the signer does not view the message content, but a third party can ofr verify the signature and know that the signature is valid within the limitations of the underlying signature scheme. This intuition of not learning anything is hard to capture in mathematical terms.
Blind signatures are typically employed in privacy-related protocols where the signer and message author are different parties. The usual approach is to show that for every adversarial signer, there exists a simulator that can output the same information as the signer. She can place the letter in an envelope lined with carbon paper and send it to Bob. From Wikipedia, the free encyclopedia. Cryptocurrency has gained unprecedented attention since the birth of Bitcoin in The encrypted message foe usually be some secret information which the attacker observed being sent encrypted under the signer’s public key which the attacker wants to learn more about.
The blinded message is passed to a signer, who then signs it using a standard signing algorithm. Examples include cryptographic election systems and digital cash schemes. New Materials for UV Biosensor.
Digital currencies, virtual currencies, in-game currencies, etc. This can be useful in schemes where anonymity is required.
Blind Signatures for Untraceable Payments – Semantic Scholar
An unlinkable blind signature provides this guarantee, as the authority will not see the contents of any ballot it signs, and will be unable to link the blinded ballots it signs back to the un-blinded ballots it receives for counting.
Scientific Research An Academic Publisher. Blind signature schemes can be implemented using a number of common public key signing schemes, for instance RSA and Daavid. The number of transactions as well as the number of accounts held by individuals and businesses is steadily increasing.
Blind signature – Wikipedia
This page was last edited on 17 Octoberat As an analogy, consider that Alice has a letter which should be signed by an authority say Bobbut Alice does not want to reveal the content of the letter to Bob. The blind version uses a random value rsuch that r is relatively prime to N i. This includes various ” digital cash ” schemes and voting protocols.
American inventions Public-key cryptography Financial cryptography Electronic voting Digital signature schemes.
Advances in Cryptology Proceedings of Crypto. This means one vote per signed ballot in elections, for example.