|This work shows how the TPM
can give us the "cryptographic equivalent" of an envelope.
Suppose Alice wants to give Bob some data d, with the following
The slides show that if Bob has a TPM, then he can offer this service.
Alice can be sure that he cannot access the data d after he has
"returned" it to her.
- Bob can access the data at any time, without
further interaction with Alice.
- But if he chooses not to access it, he can
"return" it to Alice "unopened".
- After he has done that, Alice can be sure he
can no longer access it.