How secured are private data stored on blockchain?












3














I'm quite new in Ethereum world and I'm still little bit confused about this:
If I store any data on blockchain, is it readable from anyone? Let's say I have this is Solidity:



...

string private myVerySecretText;



function getText() external returns(string){

 require(msg.sender == something);

 return myVerySecretText;

}

...


If I'm the user that match the require statement, I can access the data, but is there some possiblity to read this data from anyone else? I know that the whole blockchain is public, so is there possible to read somehow even the private data? And can anyone read the code from my smartcontract when is deployed on a blockchain?






blockchain security private







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    3














    I'm quite new in Ethereum world and I'm still little bit confused about this:
    If I store any data on blockchain, is it readable from anyone? Let's say I have this is Solidity:



    ...
    
string private myVerySecretText;
    

    
function getText() external returns(string){
    
 require(msg.sender == something);
    
 return myVerySecretText;
    
}
    
...


    If I'm the user that match the require statement, I can access the data, but is there some possiblity to read this data from anyone else? I know that the whole blockchain is public, so is there possible to read somehow even the private data? And can anyone read the code from my smartcontract when is deployed on a blockchain?






    blockchain security private







    share|improve this question







    New contributor




    Banana Cake is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
    Check out our Code of Conduct.























      3












      3








      3







      I'm quite new in Ethereum world and I'm still little bit confused about this:
      If I store any data on blockchain, is it readable from anyone? Let's say I have this is Solidity:



      ...
      
string private myVerySecretText;
      

      
function getText() external returns(string){
      
 require(msg.sender == something);
      
 return myVerySecretText;
      
}
      
...


      If I'm the user that match the require statement, I can access the data, but is there some possiblity to read this data from anyone else? I know that the whole blockchain is public, so is there possible to read somehow even the private data? And can anyone read the code from my smartcontract when is deployed on a blockchain?






      blockchain security private







      share|improve this question







      New contributor




      Banana Cake is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.











      I'm quite new in Ethereum world and I'm still little bit confused about this:
      If I store any data on blockchain, is it readable from anyone? Let's say I have this is Solidity:



      ...
      
string private myVerySecretText;
      

      
function getText() external returns(string){
      
 require(msg.sender == something);
      
 return myVerySecretText;
      
}
      
...


      If I'm the user that match the require statement, I can access the data, but is there some possiblity to read this data from anyone else? I know that the whole blockchain is public, so is there possible to read somehow even the private data? And can anyone read the code from my smartcontract when is deployed on a blockchain?






      blockchain security private




      blockchain security private






      share|improve this question







      New contributor




      Banana Cake is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.











      share|improve this question







      New contributor




      Banana Cake is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.









      share|improve this question




      share|improve this question






      New contributor




      Banana Cake is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.









      asked yesterday









      Banana CakeBanana Cake

      182




      182




      New contributor




      Banana Cake is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.





      New contributor





      Banana Cake is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.






      Banana Cake is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.






















          1 Answer
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          active

          oldest

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          3














          All the data in the Blockchain is public. The "public" keyword creates a getter for the variable, (a function that return the value). When you make it private the getter is not created but you can access the storage of the contract. web3 allows you to read the storage using:



          web3.getStorageAt(address, position)


          see this for more info



          Hope this helps






          share|improve this answer





















          • Thank you. And are the data readable after the getStorageAt function or is it in some format/ data type that is not readable and can't be transferred to a readable form? I'm asking because I want to store there some private data and I'm not sure if is necessary to use some encryption or I can just let it be only as it is..
            – Banana Cake
            yesterday








          • 1




            web3 will return a number in hexadecimal. If the information is private you should encrypt it. If this answered your question please accept the answer.
            – Jaime
            yesterday












          • Thank you. One more question - are the data passed into a smart contract function in transaction visable? Let's say I want to call function SetSecretText(string newText) external ... (inside the function is some encryption). Is the value of newText parameter in a transaction visable also publicly?
            – Banana Cake
            11 hours ago








          • 1




            yes, it is visible so the encryption should be done offline such that the data that you send is already encrypted.
            – Jaime
            9 hours ago






          • 1




            yes, every transaction that has happened in the network is visible.
            – Jaime
            9 hours ago











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          1 Answer
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          1 Answer
          1






          active

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          active

          oldest

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          active

          oldest

          votes









          3














          All the data in the Blockchain is public. The "public" keyword creates a getter for the variable, (a function that return the value). When you make it private the getter is not created but you can access the storage of the contract. web3 allows you to read the storage using:



          web3.getStorageAt(address, position)


          see this for more info



          Hope this helps






          share|improve this answer





















          • Thank you. And are the data readable after the getStorageAt function or is it in some format/ data type that is not readable and can't be transferred to a readable form? I'm asking because I want to store there some private data and I'm not sure if is necessary to use some encryption or I can just let it be only as it is..
            – Banana Cake
            yesterday








          • 1




            web3 will return a number in hexadecimal. If the information is private you should encrypt it. If this answered your question please accept the answer.
            – Jaime
            yesterday












          • Thank you. One more question - are the data passed into a smart contract function in transaction visable? Let's say I want to call function SetSecretText(string newText) external ... (inside the function is some encryption). Is the value of newText parameter in a transaction visable also publicly?
            – Banana Cake
            11 hours ago








          • 1




            yes, it is visible so the encryption should be done offline such that the data that you send is already encrypted.
            – Jaime
            9 hours ago






          • 1




            yes, every transaction that has happened in the network is visible.
            – Jaime
            9 hours ago
















          3














          All the data in the Blockchain is public. The "public" keyword creates a getter for the variable, (a function that return the value). When you make it private the getter is not created but you can access the storage of the contract. web3 allows you to read the storage using:



          web3.getStorageAt(address, position)


          see this for more info



          Hope this helps






          share|improve this answer





















          • Thank you. And are the data readable after the getStorageAt function or is it in some format/ data type that is not readable and can't be transferred to a readable form? I'm asking because I want to store there some private data and I'm not sure if is necessary to use some encryption or I can just let it be only as it is..
            – Banana Cake
            yesterday








          • 1




            web3 will return a number in hexadecimal. If the information is private you should encrypt it. If this answered your question please accept the answer.
            – Jaime
            yesterday












          • Thank you. One more question - are the data passed into a smart contract function in transaction visable? Let's say I want to call function SetSecretText(string newText) external ... (inside the function is some encryption). Is the value of newText parameter in a transaction visable also publicly?
            – Banana Cake
            11 hours ago








          • 1




            yes, it is visible so the encryption should be done offline such that the data that you send is already encrypted.
            – Jaime
            9 hours ago






          • 1




            yes, every transaction that has happened in the network is visible.
            – Jaime
            9 hours ago














          3












          3








          3






          All the data in the Blockchain is public. The "public" keyword creates a getter for the variable, (a function that return the value). When you make it private the getter is not created but you can access the storage of the contract. web3 allows you to read the storage using:



          web3.getStorageAt(address, position)


          see this for more info



          Hope this helps






          share|improve this answer












          All the data in the Blockchain is public. The "public" keyword creates a getter for the variable, (a function that return the value). When you make it private the getter is not created but you can access the storage of the contract. web3 allows you to read the storage using:



          web3.getStorageAt(address, position)


          see this for more info



          Hope this helps







          share|improve this answer












          share|improve this answer



          share|improve this answer










          answered yesterday









          JaimeJaime

          5,0171217




          5,0171217












          • Thank you. And are the data readable after the getStorageAt function or is it in some format/ data type that is not readable and can't be transferred to a readable form? I'm asking because I want to store there some private data and I'm not sure if is necessary to use some encryption or I can just let it be only as it is..
            – Banana Cake
            yesterday








          • 1




            web3 will return a number in hexadecimal. If the information is private you should encrypt it. If this answered your question please accept the answer.
            – Jaime
            yesterday












          • Thank you. One more question - are the data passed into a smart contract function in transaction visable? Let's say I want to call function SetSecretText(string newText) external ... (inside the function is some encryption). Is the value of newText parameter in a transaction visable also publicly?
            – Banana Cake
            11 hours ago








          • 1




            yes, it is visible so the encryption should be done offline such that the data that you send is already encrypted.
            – Jaime
            9 hours ago






          • 1




            yes, every transaction that has happened in the network is visible.
            – Jaime
            9 hours ago


















          • Thank you. And are the data readable after the getStorageAt function or is it in some format/ data type that is not readable and can't be transferred to a readable form? I'm asking because I want to store there some private data and I'm not sure if is necessary to use some encryption or I can just let it be only as it is..
            – Banana Cake
            yesterday








          • 1




            web3 will return a number in hexadecimal. If the information is private you should encrypt it. If this answered your question please accept the answer.
            – Jaime
            yesterday












          • Thank you. One more question - are the data passed into a smart contract function in transaction visable? Let's say I want to call function SetSecretText(string newText) external ... (inside the function is some encryption). Is the value of newText parameter in a transaction visable also publicly?
            – Banana Cake
            11 hours ago








          • 1




            yes, it is visible so the encryption should be done offline such that the data that you send is already encrypted.
            – Jaime
            9 hours ago






          • 1




            yes, every transaction that has happened in the network is visible.
            – Jaime
            9 hours ago
















          Thank you. And are the data readable after the getStorageAt function or is it in some format/ data type that is not readable and can't be transferred to a readable form? I'm asking because I want to store there some private data and I'm not sure if is necessary to use some encryption or I can just let it be only as it is..
          – Banana Cake
          yesterday






          Thank you. And are the data readable after the getStorageAt function or is it in some format/ data type that is not readable and can't be transferred to a readable form? I'm asking because I want to store there some private data and I'm not sure if is necessary to use some encryption or I can just let it be only as it is..
          – Banana Cake
          yesterday






          1




          1




          web3 will return a number in hexadecimal. If the information is private you should encrypt it. If this answered your question please accept the answer.
          – Jaime
          yesterday






          web3 will return a number in hexadecimal. If the information is private you should encrypt it. If this answered your question please accept the answer.
          – Jaime
          yesterday














          Thank you. One more question - are the data passed into a smart contract function in transaction visable? Let's say I want to call function SetSecretText(string newText) external ... (inside the function is some encryption). Is the value of newText parameter in a transaction visable also publicly?
          – Banana Cake
          11 hours ago






          Thank you. One more question - are the data passed into a smart contract function in transaction visable? Let's say I want to call function SetSecretText(string newText) external ... (inside the function is some encryption). Is the value of newText parameter in a transaction visable also publicly?
          – Banana Cake
          11 hours ago






          1




          1




          yes, it is visible so the encryption should be done offline such that the data that you send is already encrypted.
          – Jaime
          9 hours ago




          yes, it is visible so the encryption should be done offline such that the data that you send is already encrypted.
          – Jaime
          9 hours ago




          1




          1




          yes, every transaction that has happened in the network is visible.
          – Jaime
          9 hours ago




          yes, every transaction that has happened in the network is visible.
          – Jaime
          9 hours ago










          Banana Cake is a new contributor. Be nice, and check out our Code of Conduct.










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