Rerandomisation & Incremental Spend
Each zk-nym credit will not be valid for the entire amount of data that the credential aggregated from the PSCs is; if the aggregated credential is worth (e.g.) 10GB of Mixnet data, each credit will be worth far less (e.g. 100MB). This amount will be globally uniform in order to avoid situations where differently sized credits allow for patterns to emerge.
The functionality included in the following code block examples were added to the nym-cli tool for illustrative purposes only: this is not necessarily how credentials will be accessed in the future.
Furthermore, the nym-cli uses the words 'tickets' in place of 'credits' and 'ticketbook' in place of 'aggregated credential': this is wording that we are moving away from now in place of the simpler credential/credit. This will be updated in the nym-cli tool in a future release.
The numbers used in this high level overview are for illustration purposes only. The figures used in production will potentially vary. Note that individual zkNym sizes will be uniform across the Network.
Why not spend the entire credential at once?
This is to account for the need for a client to change their ingress Gateway, either because the Gateway itself has gone down / is not offering the required bandwidth, or because a user might simply want to split their traffic across multiple Gateways for extra privacy.
This means that clients are not tied to particular Gateways they have 'spent' their entire subscription amount with; if the ingress Gateway goes down, or the client simply wishes to use another ingress Gateway, the user has multiple other zk-nym credits they can use that account for their remaining purchased bandwidth.
Going back to the nym-cli tool to illustrate this; we can generate multiple unlinkable credits ('tickets' on this command output) from a single aggregated credential ('ticketbook' below):
❯ ./nym-cli ecash generate-ticket --credential-storage storage.db --provider 6qidVK21zpHD298jdDa1RRpbRozP29ENVyqcSbm6hQrG --full
TICKETBOOK DATA:
4Ys9pzUf9MPxX4s5RASyrRoY9fPk1a1kFuPBP2jm2L5PyUy535yPEfjHAfpUTC1Lf2d155TmjukvcDycQYfBSDfhEUJM4J3qPNfG3B5aQEEkefESZp3CM5AEnAu1AEyhpepbYw6BuXokiNcmaYtq3yJQbA4KicKP8FowoRzKHmXpJoUqY8wYQughGfdtXgr3rVaZmK21X51P1NL2UW1aCE512WWfy6P1LJHByWywT3qVw28Z83
generating payment information for 50 tickets. this might take a while!...
AVAILABLE TICKETS
+-------+---------------------------------------------------------------------------------------------------------------------------------------------------------------+--------------------+
| index | binary data | spend status |
+============================================================================================================================================================================================+
| 0 | 4kgKyJLq1zQuk9r9AbEFHPqD8mDuxsLSjgo9XW4Lf7EqGSbgfNsWSEcTbRPEMFLzpstbX5azsA3opFh851h4g5qCG2qE3Luwqua4GG2ebJhk91rvEc5JPctbVQxL62fkfQ6svdcNp…1057bytes remaining | NOT SPENT |
|-------+---------------------------------------------------------------------------------------------------------------------------------------------------------------+--------------------|
| 1 | 4kefQqViRZd5YezMHH1FTcgUGPK2E2ivfmwgf59exvsnR8tsb5aJtGVwpA7wAJT6icPeo8jtDwDZ3WMPJxL3VRLiakAQr79zh7ixM89gowg3ChHEy6ewmHcT7T6RFkZFsMCMj1CNd…1057bytes remaining | NOT SPENT |
|-------+---------------------------------------------------------------------------------------------------------------------------------------------------------------+--------------------|
| 2 | 4kxaKdBxyFzJ8gxSZCh1v3wBfN7JvnCJuoJ4MWqkkMHtt2XgRKbDmHCv5ZxtA57Qk8LC3NDMBmqjADvY34mAPdT3tLBL4uxse9ASa227Ji96dwgxvfbpvLXSSr5o4vuPRV9K7UfpJ…1057bytes remaining | NOT SPENT |
|-------+---------------------------------------------------------------------------------------------------------------------------------------------------------------+--------------------|
| 3 | 4kdYwUJwXyxZBLQXextd4GsU2MATjzArVq5Ec459fTXyrm6q3vxurWULzBMpV5UjcmjJtnw1zFqt7f8Ydu5gyxwAVXP3Nwpn83ouguv2n4YrUewZCvFAqQYXgahhhaQGp6RxK2Arh…1057bytes remaining | NOT SPENT |
|-------+---------------------------------------------------------------------------------------------------------------------------------------------------------------+--------------------|
...
| 46 | 4kg8bfQ7kGgq5TkkqXagpAEu95gmGT4i7NKbaxJtp2gRgWRrQZM1rxaDAzAxfghoM6PFNbYgKsnLD4MF8HtXW3p92CnPBjswzJ1EbtsMGpgDER3CYFt2ivAhMAVXFziF5UjVJXhpa…1057bytes remaining | NOT SPENT |
|-------+---------------------------------------------------------------------------------------------------------------------------------------------------------------+--------------------|
| 47 | 4kipbH5Fqt5E9hFMynm9vzFh5FkxKRdHrSEiiJWDwmg3mASctR61sXoFD5u5ZMBwGdvz9sWsRfrpR4MX2NNfRhC85aUxqtkAv3hXZiCLtE1pUC54Cq7YXHyv2XTNKpvuFZs2GmwYg…1057bytes remaining | NOT SPENT |
|-------+---------------------------------------------------------------------------------------------------------------------------------------------------------------+--------------------|
| 48 | 4kxYZ26HXvxVhh4quHXeCUyQokydeF5wkwUi8fMx6P3uoMvuiPaNP1SJTbYnaQEFFtF6U4dGop6QckUYvbtwQFoGJTJesHFHTDtHbshj5Dg8DwbyaHuAR86zGwYMUPved4XKUTMLa…1057bytes remaining | NOT SPENT |
|-------+---------------------------------------------------------------------------------------------------------------------------------------------------------------+--------------------|
| 49 | 4kb6zmPebRxjKLVicctq2whvANjWJMoohiPBMr21cT4xj78nvXmJEK8EB4PpqQVFo6ddU9uzuer5ggQZNZgETX2VXBzymBYNzXBuXjLJi1WRdAiASqWz5Hv5im1TJh4XBE4mxKo8Q…1057bytes remaining | NOT SPENT |
+-------+---------------------------------------------------------------------------------------------------------------------------------------------------------------+--------------------+