The trick is, that every time you create a new credential, it's serial number is scrambled/blinded.
And whenever you spend or present a credential, then you must unblind the serial number.
So, the coordinator sees a random blinded cyphertext when the credential is created, and he sees a different random unblinded serial number when the credential is presented.
This is theoretically perfect privacy, meaning Esch credential looks indistinguishably random with the anonymity set of all users of this time period.
Max Hillebrand
npub1kl…lx3vt
2023-02-26 09:53:32
in reply to nevent1q…kez9
Author Public Key
npub1klkk3vrzme455yh9rl2jshq7rc8dpegj3ndf82c3ks2sk40dxt7qulx3vtPublished at
2023-02-26 09:53:32Event JSON
{
"id": "3c88422f78b9e4ceb150b297952ef06af4331386f77a332eb91005ef6a41c835",
"pubkey": "b7ed68b062de6b4a12e51fd5285c1e1e0ed0e5128cda93ab11b4150b55ed32fc",
"created_at": 1677405212,
"kind": 1,
"tags": [
[
"e",
"11f1b2b960beb24c926562b72daab0404373bf5dbc5cb29680127ac79aafdff3"
],
[
"e",
"f7c0f7829fe2883b5a410c37602d0c85c061c3c4999837e6c19606bd68afa6c6"
],
[
"e",
"137773e9c1cef6bf87e351d9dcc39b49e3f1fd9127cd22bd48dd375caecccf4d"
],
[
"p",
"b7ed68b062de6b4a12e51fd5285c1e1e0ed0e5128cda93ab11b4150b55ed32fc"
],
[
"p",
"fa984bd7dbb282f07e16e7ae87b26a2a7b9b90b7246a44771f0cf5ae58018f52"
]
],
"content": "The trick is, that every time you create a new credential, it's serial number is scrambled/blinded. \n\nAnd whenever you spend or present a credential, then you must unblind the serial number. \n\nSo, the coordinator sees a random blinded cyphertext when the credential is created, and he sees a different random unblinded serial number when the credential is presented.\n\nThis is theoretically perfect privacy, meaning Esch credential looks indistinguishably random with the anonymity set of all users of this time period.",
"sig": "c5273a224b3d77128a71d7f2f70a4425fbceb5da3371c8ec24955f1027bd920a4f1ca90f3e82b205b2274a5d47207ec478daca41aca00889d6c7725fb68c2792"
}