malleable

adjective3

1. •
   Able to be hammered into thin sheets; capable of being extended or shaped by beating with a hammer, or by the pressure of rollers.
2. •
   (figurative) Flexible, liable to change.

   • My opinion on the subject is malleable.
3. •
   in which an adversary can alter a ciphertext such that it decrypts to a related plaintext