ENCRYPTION
STEP 1
Alice encrypts her secret, and splits up the decryption key
STEP 2
She sends the decryption key shares to the Trustees
STEP 3
Similar to trustees, validators ensure that only legitimate persons can access a secret. They also observe the ledger and respond to legitimate requests.
DECRYPTION
STEP 4
If or when Bob needs access to the information, he submits a decryption request to the ledger
STEP 5
Trustees see the request and publish their secret shares
STEP 6
Once a threshold number of trustees have published their shares, Bob can reconstruct the data
THE
PROTOCOL
Robust, cryptographically
enforced transparency
With our protocol, it’s possible for a sharer (Alice) to have certainty that a secret has not been decrypted by the recipient (Bob) until he chooses to decrypt it.
Trustees
Trustees are the partially trusted keepers of the means of accessing Alice’s secret. The means of decryption are spread across multiple trustees, so that no one entity can control access. They observe the ledger for access requests and share the means of access.
Accountability ledger
Central to the transparency of decryption in PAD is the ledger. By observing this ledger, Alice can determine whether and by whom, a secret has been decrypted.
Decryption
When Bob needs to access the secret, he posts his request to the accountability ledger. The trustees respond automatically with their secret shares - Alice does not need to participate in an additional transaction.