How can I ethically store sensible data in a way they could be retrieved?
I am facing a design/ethical issue. I want to make email aliases. The user gives up an email address and options (the alias is available for *n* days / *n* emails, etc.). Then the system returns an email alias. That can be use :

 - To combat spam ;
 - For security purposes (anonymization).

Several web tools already exist but none can ethically promise that they cannot give emails, or send spam, or eventually give mail addresses to a government if there is a search.
The main problem is that whenever a mail is sent to the email alias address, the system must redirect to the true one.

For these reasons, we also cannot do it with gpg keys or homomorphic encryption...
How can I ethically store sensible data in a way they could be retrieved?
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I am facing a design/ethical issue. I want to make email aliases. The user gives up an email address and options (the alias is available for *n* days / *n* emails, etc.). Then the system returns an email alias. That can be use :

 - To combat spam ;
 - For security purposes (anonymization).

Several web tools already exist but none can ethically promise that they cannot give emails, or send spam, or eventually give mail addresses to a government if there is a search.
The main problem is that whenever a mail is sent to the email alias address, the system must redirect to the true one.

For these reasons, we also cannot do it with gpg keys or homomorphic encryption...