A remote controlled browser to create screenshots with
extended logging of user actions and data transfer to create
a timestamped and digitally signed document to
give a very reliable proof of the website contents while
allowing to selectively exclude sensitive information
and transparently decoding ssl (https) sessions
NEW ! LTV and PDF A/1-B compliant
Typical usage scenarios:
Prove that an image was offered under creative commons license
Prove to your professor that you cited that webpage correctly
Prove your acomplishments in a game (if that game displays them on a
Prove to your mother that your sister wrote something stupid in
her/your social media account although she will delete it.
Prove to that website service technican, that this “
unreproducable ” error on his site actually can be reproduced
other types of ediscovery or evidence generation
What is a digitally signed Document?
A digitally signed document contains additional information: A digital
signature. This is a mathematical construct so tightly interwoven with the document that it is destroyed if the document is
The digital signature is a sequence of numbers that together with the name of the signer and a so called
hash-value denotes one solution to a complicated mathematical equation. The
hash-value is the result of a mathematical function using all parts of the
document as its input. This function has been designed to map small changes
of the document to different values. So modifying any part of the document
will change this hash-value invalidating the equation mentioned at the
beginning. To make this valid again the name of the signer and/or the
signature have to be adapted. The equation is so complicated that finding a
new adapted signature is so difficult that one needs some secret informaton
to do so. The certification authorities choose the equations (adjust further
parameters) in a way that solving needs data only hold by the
How do I recognize digitally signed documents ?
Many PDF-viewers e.g. AdobeReader
verify and display digital signatures.
A PDF-file signed by ICanProve.de looks like this:
AdobeReader reports a digital signature but flags it UNKNOWN.
AdobeReader can use certificates for digital signatures from different sources.
The certificate used by IcanProve.de has not been commissioned by Adobe but
by a different company that cooperates with many oparating system vendors.
Therefore certificates stored by the operating system have to be applied for
verification. To enable these (using Windows) choose
Edit → Preferences → Signatures → Verification → More → Windows-Integration
and check the two boxes.
Should I trust this page with my passwords?
You should not. I have
been very cautious and have implemented many security mechanisms, but every
website can be hacked and furthermore you do not know me at all. So if you
absolutely need to enter secret passwords please change them immediately
afterwards. Never ever enter transaction codes.
How do you handle spectre and meltdown?
Spectre variants might allow to steal data from other processes on the same machine, even
when separated by virtualization. Therefore we cannot be sure at the moment that
your browsing process cannot be seen by others. But we try to keep up with
all the patches (microcode, OS and browser) so that the needed zero time
exploits will be too expensive for almost anyone to use.
The signing process has been transferred to a (physical) different machine
where the key is protected by a TPM 2.0 module. This combination should not
be vulerable to spectre or meltdown on the computer used for browsing.
(Stealing the passwort of the signing computer by spectre will not help an
attacker as this machine is not reachable from any other system at all.)