Top Secret's Pros & Cons

Pros

Strong encryption

• Advanced Encryption Standard used by the US government
• Spatial hashing algorithm

Unlimited secret size into PDF files

Multiple Data Passwords allows file distribution granting the users to read specific parts only of the whole secret

Multiple Master Passwords (PDF only, images under conditions) allows file distribution granting the users to read an isolated secret without even knowing any other secrets are embedded.

Cons

PNG and JPEG images are easy to "sanitize" (i.e. destroying the secret)

• Resize
• Rotate
• Crop
• Load/Save (Jpeg)

Such images should be sent as documents over social networks to avoid any reprocessing.