1. A computing device having one or more components implemented at least in part in hardware and that perform acts comprising: obtaining data to be sealed and one or more conditions that are to be satisfied in order for the data to be unsealed; sealing the data in response to a request by a caller by encrypting, in the computing device and using public key encryption, both the data and the one or more conditions to generate a ciphertext that includes both the encrypted data and the encrypted one or more conditions, the data not being unsealed if the one or more conditions are not satisfied, the one or more conditions including a program to be executed and the one or more conditions being satisfied only if execution of the program returns an indication of true; and returning the ciphertext to the caller.