The difference is the safe, or safe deposit box, can be opened without assistance from the suspect. There is no testimony required. I don’t have an issue with the seizure of the laptop or the encryption being broken and the information retrieved. It is requiring the suspect to give up their “right to remain silent” by forcing testimony from them.
An interesting point is that the Supreme Court has ruled that a person can not be compelled to give up the combination numbers for a safe, lock etc. They have ruled that a person can be compelled to give up the key to a lock, safe etc. The difference in the court rulings is that the key is a physical object and the combination is not. I think a password should be equated to a combination as it isn’t anything physical. A password is akin to a combination, IMO.
The US Supreme Court case that first addressed the issue of forcing and individual to divulge a lock combination is here: http://www.law.cornell.edu/supremecourt/text/487/201
The majority did agree with the dissent argument in that forcing the combination to be revealed was akin to giving testimony and violated Fifth Amendment rights. Here is an outtake from the majority response:
[I][B]We do not disagree with the dissent that “[t]he expression of the contents of an individual’s mind” is testimonial communication for purposes of the Fifth Amendment. Post, at 220, n. 1. We simply disagree with the dissent’s conclusion that the execution of the consent directive at issue here forced petitioner to express the contents of his mind. In our view, such compulsion is more like “be[ing] forced to surrender a key to a strongbox containing incriminating documents” than it is like “be[ing] compelled to reveal the combination to [petitioner’s] wall safe.” Post, at 219.[/B][/I]
Basically, the ruling and dissenting opinions both agree that forcing a person to reveal a combination is a violation of their Fifth Amendment rights. The interesting phrase, IMO, from the above is that they see divulging a combination is “[t]he expression of the contents of an individual’s mind.” If this goes to the US Supreme Court then I think this ruling will be overturned. Demanding a password is definitely requires the person to express the contents of their mind.