System and method for electronic transactions

Abstract

A system and method for performing an electronic transaction, including registration, audit and trusted recovery features. A transaction request message is received from a registered user that includes an unblinded validated certificate, and a blinded unvalidated certificate. If the unblinded validated certificate is determined to be legitimate, then a transaction can be performed, and the blinded unvalidated certificate is validated to obtain a blinded, validated certificate that is sent to the user. An audit protocol can be used to further verify the legitimacy of the transaction request message, and a user can recover from a broken connection by replaying a protocol run.

1 . A method for initializing an electronic voting transactions using a computer processor, the method comprising 
 a. receiving at the computer processor a voter registration request message that atomically binds 
 i. voting authorization data, and  
 ii. a blinded unvalidated vote certificate to be validated;  
   b. determining by using the computer processor if the vote authorization data is valid;    c. if the vote authorization data is valid, then validating the blinded unvalidated vote certificate by using the computer processor to obtain a blinded validated vote certificate; and    d. sending a registration response message from the computer processor to a voter that includes the blinded validated vote certificate atomically bound to the registration request message.    
   
   
       2 . The method of  claim 1 , further comprising the step of receiving a voter acknowledgment message at the computer processor from a voter acknowledging that the voter has received the registration response message.  
   
   
       3 . The method of  claim 1 , wherein the registration request message includes a nonce, a session key and a blinding factor applied to the nonce, and further comprising the step of storing the registration request message and the registration response message in a recovery database at the computer processor.  
   
   
       4 . A method for recovering from an interruption in initializing an electronic voting transaction in a computer processor, comprising the steps of: 
 a. receiving a first registration request message at the computer processor from a voter that includes a nonce, a session key, and a blinding factor applied to the nonce, and that atomically binds 
 i. vote authorization data, and  
 ii. a blinded unvalidated vote certificate to be validated;  
   b. storing the registration request message in a recovery database in the computer processor;    c. determining by using the computer processor if the vote authorization data is valid;    d. if the vote authorization data is valid, then validating the blinded unvalidated vote certificate using the computer processor to obtain a blinded validated vote certificate;    e. sending a first registration response message from the computer processor to a voter that includes the blinded validated vote certificate atomically bound to the registration request message;    f. storing the first registration response message in a recovery database in the computer processor;    g. receiving a second registration request message at the computer processor;    h. determining if the second registration request message has the same nonce, session key, and blinding factor applied to the nonce as the first registration request message stored in the recovery database of the computer processor;    i. if the second registration message has the same nonce, session key, and blinding factor applied to the nonce as the first registration request message, then 
 1. retrieving the first registration response message from the recovery database of the computer processor; and  
 2. sending the first registration response message from the computer processor to the voter.  
   
   
   
       5 . A method for performing an electronic voting transaction using a computer processor, comprising the steps of: 
 a. receiving a voting request message at the computer processor that atomically binds 
 i. an unblinded vote certificate, and  
 ii. a blinded unvalidated vote certificate to be validated;  
   b. determining by using the computer processor if the unblinded vote certificate is valid; and    c. if the unblinded vote certificate is valid, then generating a vote transaction response by using the computer processor that includes: 
 i. validating the blinded unvalidated vote certificate to obtain a validated blinded vote certificate, and  
 ii. sending the validated blinded vote certificate atomically bound to the voting transaction request message from the computer processor to a voting transaction response recipient in a vote transaction response message.  
   
   
   
       6 . The method of  claim 5 , wherein the vote certificate indicates a yes or a no vote.  
   
   
       7 . The method of  claim 5 , wherein the parity of the certificate indicates a yes or a no vote.  
   
   
       8 . The method of  claim 5 , further comprising the step of receiving a transaction acknowledgment message at the computer processor from a transaction response recipient acknowledging that the transaction response recipient has received the voting transaction response message.  
   
   
       9 . The method of  claim 5 , further comprising the step of storing the voting transaction request message and the voting transaction response message in a recovery database at the computer processor.  
   
   
       10 . A method for recovering from an interruption in an electronic voting transaction occurring within a computer processor, comprising the steps of: 
 a. receiving a first voting transaction request message at the computer processor that includes a session key, a nonce and a blinding factor applied to the nonce, and that atomically binds 
 i. an unblinded vote certificate, and  
 ii. a blinded unvalidated vote certificate to be validated;  
   b. storing the first voting transaction request message in a recovery database in the computer processor;    c. determining if the unblinded vote certificate is valid; and    d. if the unblinded vote certificate is valid, then generating in the computer processor a voting transaction response that includes 
 i. validating the blinded unvalidated vote certificate to obtain a validated blinded vote certificate,  
 ii. sending the validated blinded vote certificate atomically bound to the voting transaction request message from the computer processor to a voting transaction response recipient in a first voting transaction response message, and  
 iii. storing the first voting transaction response message in a recovery database within the computer processor;  
   e. receiving a second voting transaction request message at the computer processor that includes a session key, a nonce and a blinding factor applied to the nonce, and atomically binds 
 i. an unblinded voting certificate, and  
 ii. a blinded unvalidated voting certificate to be validated;  
   f. determining by using the computer processor if the second voting transaction request message has the same nonce, session key, and blinding factor applied to the nonce as the first voting transaction request message stored in the recovery database in the computer processor; and    g. if the second voting transaction request message has the same nonce, session key, and blinding factor applied to the nonce as the first voting transaction request message, then 
 i. retrieving the first voting transaction response message from the recovery database in the computer processor, and  
 ii. sending the first voting transaction response message from the computer processor to the voting transaction response recipient.  
   
   
   
       11 . A method for auditing an electronic voting transaction using a computer processor, comprising the steps of: 
 a. receiving a voting transaction request message at the computer processor that atomically binds 
 i. an unblinded vote certificate,  
 ii. a blinded unvalidated vote certificate to be validated, and  
 iii. blinded vote audit data;  
   b. sending a vote audit request message atomically bound to the vote transaction request message from the computer processor to a voter;    c. receiving at the computer processor vote audit response message atomically bound to the vote audit transaction message wherein the vote audit response message includes vote audit response data; and    d. determining by using the computer processor if the blinded vote audit data is valid using the vote audit response data.    
   
   
       12 . The method of  claim 11 , wherein the vote audit response data is determined by the computer processor to be valid if 
 i. the vote audit response data corresponds to the blinded vote audit data received at the computer processor in the voting transaction request message, and    ii. the vote audit response data is legitimate.    
   
   
       13 - 27 . (canceled)