A method for encryption and sealing of a plaintext file by hashing the plaintext file to produce a plaintext hash, encrypting the plaintext file to produce ciphertext, hashing the ciphertext to produce a ciphertext hash, hashing the plaintext hash and the ciphertext hash to produce a result hash, and sealing the ciphertext together with the result hash. This provides verification for non-repudiation and protects against undetected malware corrupting the plaintext or ciphertext files.