WO2014098745A1

WO2014098745A1 - Methods and apparatuses in a data communication system for proving authenticity of electronically signed human readable data

Info

Publication number: WO2014098745A1
Application number: PCT/SE2013/051539
Authority: WO
Inventors: Lukas DUCZKO; Magnus Carlsson
Original assignee: Scrive Ab
Priority date: 2012-12-19
Filing date: 2013-12-17
Publication date: 2014-06-26

Abstract

The present invention deals with a method performed by a communication apparatus (130, 135) of a data communication system for proving authenticity of electronically signed documents, the data communication system comprising the communication apparatus and a server (120). The method comprises receiving an invitation to electronically sign the document, presenting the document at a screen of the communication apparatus and detecting that a process of signing the human readable data is being performed. Thereafter, in response to detecting that a process of signing the human readable data is being performed, a screen-shot is taken of the screen, and the recorded screen-shot is sent to the server. At the server, another method is performed which appends the screen-shot to the electronically signed document and stores the screen-shot together with the electronically signed document for later use as evidence of a performance of the signing process. Further, the electronically signed document with its appended screen shot may in its turn be digitally signed and sealed, as a joint package.

Description

METHODS AND APPARATUSES IN A DATA COMMUNICATION SYSTEM FOR PROVING AUTHENTICITY OF ELECTRONICALLY SIGNED HUMAN

READABLE DATA

Technical field

[0001 ] The present disclosure relates generally to methods and apparatuses in a data communication system for proving authenticity of electronically signed human readable data. More particularly, the present disclosure relates to a method in a communication apparatus, a communication apparatus, a method in a server and a server of a data communication system for proving authenticity of electronically signed human readable data.

Background

[0002] The process of signing a document, such as an agreement between two parties, can be done in many ways. Traditionally the document has been a paper document that has been signed by hand. With the digital age the paper document standard has evolved into alternative document formats such as a printed fax and a scanned PDF copy.

[0003] New alternative document formats have been introduced to reduce transaction costs. Usually this comes at the price of documents with decreased evidence qualities. For example, scanned PDF copies are mutable documents without traceability in case of forgery and the fingerprints in the originally signed paper are not captured in the scanned PDF copy. This makes the scanned PDF copy a weak container of legal evidence that is by nature more dependent than paper on external evidence to support its case. External evidence necessary may be e.g. related emails.

[0004] In recent years there has evolved a plethora of software solutions for signing documents electronically. Whilst these solutions have further lowered transaction costs, the issues with decreasing document evidence qualities are not often addressed. There is no known prior art-solution that could fully bring back document evidence quality to the level of printed-paper. [0005] Further, when the document to be signed is a digital document presented on a screen, it needs to be proven that the document shown on the screen has the same content and appearance as the subsequently signed and stored document, such that it can be guaranteed that the parties signing the document understood that they were signing and what they were signing.

[0006] If there is a dispute regarding authenticity of an electronically signed document, for example in court, it may be necessary to prove for example that the parties signing the document understood that they were signing and what they were signing. To prove this, the ability to easily and accurately show what was presented on the screen at the moment of signing is vital.

[0007] Consequently, there may be a need for a solution for proving authenticity of electronically signed documents.

Summary

[0008] It is an object of the invention to address at least some of the problems and issues outlined above. It is an object to prove authenticity of electronically signed human readable data, such as electronic documents, e.g. agreements signed electronically. It is another object to be able to prove that human readable data in electronic format, such as an electronic document, was signed properly and/or to prove that the person signing the document should have understood what kind of document he/she signed and that he/she was undertaking a signing process. It is possible to achieve at least one of these objects and others by using methods and apparatuses as defined in the attached independent claims.

[0009] According to a first aspect, a method is provided performed by a communication apparatus of a data communication system for proving authenticity of electronically signed human readable data, the data communication system comprising the communication apparatus and a server. The method comprises receiving an invitation to sign the human readable data, presenting the human readable data at a man-machine interface, MMI, of the communication apparatus and detecting that a process of signing the human readable data is being performed. The method further comprises recording a state of the MMI comprising the human readable data, in response to detecting that a process of signing the human readable data is being performed and sending the recorded MMI state to the server.

[00010] The method of the first aspect further co-operates with a corresponding method according to a second aspect. According to the second aspect, a method is provided performed by a server of the data communication system for proving authenticity of electronically signed human readable data. The method comprises sending an invitation to sign the human readable data to the communication apparatus, receiving a recorded MMI state of the apparatus, from the apparatus, wherein the MMI state has been recorded in connection with a process of signing the human readable data, and appending the recorded MMI state to the signed human readable data.

[0001 1 ] By such methods, an evidence of the signing of the human readable data has been captured and stored together with the signed human readable data, which evidence may be used for at a later instance proving that the signing party actually was signing and understood what he/she was signing.

[00012] According to other aspects, corresponding communication apparatuses, servers, and computer program products for communication apparatuses and servers are also provided, the details of which will be described in the claims and the detailed description.

[00013] Further possible features and benefits of this solution will become apparent from the detailed description below.

Brief description of drawings

[00014] The solution will now be described in more detail by means of exemplary embodiments and with reference to the accompanying drawings, in which:

[00015] Fig. 1 is a block diagram illustrating a communication network in which the present invention may be used. [00016] Fig. 2 is a flow chart illustrating a method performed by a communication apparatus, according to a possible embodiment.

[00017] Fig. 3 is a flow chart illustrating a method performed by a server, according to a possible embodiment.

[00018] Fig. 4 is a block diagram illustrating a communication apparatus in more detail, according to a possible embodiment.

[00019] Fig. 5 is a block diagram illustrating a server in more detail, according to a possible embodiment.

Detailed description

[00020] A prerequisite when signing an agreement is that the signing parties understand that an agreement is entered when a signing process is being performed. Earlier, the process by which the agreement was signed was rather clear and also clearly supervised, i.e. when the signing process was performed by a pen and paper the process as such was clear and there was normally one or more person supervising the signing process, and possibly also certifying the signatures. On the other hand, when the document to be signed is a digital document presented on a screen this cannot be controlled in the same clear way. This is even more true when a cloud solution is used, i.e. when the document to be signed lies on a server and the document is presented from the server on a (remote) communication apparatus for signing. Further, the signed and stored document is not the same matter as the matter that was produced on the screen for signing by the user. Consequently, it needs to be proven that the document shown on the screen has the same content and appearance as the subsequently signed and stored document, such that it can be guaranteed that the parties signing the document understood that they were signing and what they were signing. If this cannot be guaranteed, a signing party may assert in e.g. a court in case of a dispute between parties of a signed agreement that he/she did not understand that he/she was signing an agreement and/or that he/she did not understand that it was an agreement that he/she was signing. An object of the present invention is to cater for such cases such that intent of signing the agreement can be proven, and also such that it can be proven that the document that was shown on the screen when the party signed it actually looks the same as the subsequently signed and stored document. Another object is to try to copy characteristics of a traditional manually signed paper agreement to create an evidence of intent that is independent of the provider of the technical solution for on-line signing and also independent of the provider of the evidence-of-intent solution.

[00021 ] At least one of these objects are achieved by, in a client communication apparatus receiving the electronic document, displaying the document on the Man- Machine Interface (i.e. screen) of the apparatus and recording a number of signing actions performed to the document. The signed document together with the recorded signing actions are then sent to a server for storage and possibly for forwarding of the signed document together with the recorded signing actions to the parties signing the documents and a third party. The signing actions recorded comprises recording a state of the MM I of the apparatus during the signing process, i.e by capturing a number of snap-shots of the screen of the apparatus during the time when the person signing the document actually signs the document.

[00022] Before going into other possible embodiments of the invention, a data communication system in which the present invention can be used is presented in fig. 1 . The data communication system comprises an access network 1 10, a first client communication apparatus 130, a second client communication apparatus 135 and a network server 120. The client communication apparatuses are hereinafter called apparatuses. The access network provides connections between the server 120 and the apparatuses 130, 135. The access network may be a wireless network providing wireless connection between any of the

apparatuses and a network node (not shown) out of a number of network nodes of the access network. The wireless network may be any kind of mobile

communication network, such as GSM, Wideband Code Division Multiple Access, W-CDMA, Long Term Evolution, LTE etc. The access network may also be a wireline communication network providing a wireline connection between any of the apparatuses and the server. The wireline network may be any kind of wireline technology network, such as an optical fiber network or a copper cable network. The individual apparatuses may be any kind of wireless or wireline communication apparatus, such as a computer or a mobile telephone.

[00023] Fig. 2 illustrates a method according to an embodiment of the invention, performed by a communication apparatus 130, 135 of a communication system, such as the data communication system of fig. 1 for proving authenticity of signed human readable data. The method comprises receiving 202 an invitation to sign the human readable data, presenting 204 the human readable data at a man- machine interface, MMI, of the communication apparatus and detecting 206 that a process of signing the human readable data is being performed. The method further comprises recording 208 a state of the MMI comprising the human readable data, in response to detecting that a process of signing the human readable data is being performed and sending 210 the recorded MMI state to the server.

[00024] The MMI may be an internet browser window presented on a screen. The MMI state may be current MMI output state, i.e. what the MMI looks like for the moment. The human readable data may be a document in an electronic format. The detecting that a process of signing the human readable data is being performed may be accomplished by detecting that data is being entered in a signing field of the human readable data, or any entered data signifying that a signing procedure is performed. When recording the state of the MMI also the time point when the recording was done may be recorded.

[00025] By recording what the screen looked like when the user is carrying out the process of signing digitally, and storing this recording at a server, such documentation could be brought up later for proving that the person signing understood what he/she was signing, in case of a dispute. A recording of the screen, i.e. a screen shoot is a good evidence for proving the signing experience. The person signing cannot claim having a different signing experience and it will be harder for the person signing to assert and be trusted that he/she did not understand what he/she was signing.

[00026] Fig. 3 shows a method performed by a server 120 of a data

communication system for proving authenticity of a process of signing human readable data, the data communication system may be a system as shown in fig. 1 . The method comprises sending 302 an invitation to sign the human readable data to the communication apparatus, receiving 304 a recorded MMI state of the apparatus, from the apparatus, wherein the MMI state has been recorded in connection with a process of signing the human readable data, and appending 306 the recorded MMI state to the signed human readable data. The receiving 304 may also comprise receiving the signed human readable data. The method in the apparatus as described in fig. 2 and the method in the server, as described in fig. 3 are co-operating. I.e. the communication apparatus and the server are cooperating entities.

[00027] According to an embodiment, the method described in fig. 3 may further comprise receiving a detection of an action performed to the human readable data and appending the detection of an action to the human readable data. The actions may be e.g. when the user inputs data to the document, or just scrolls the document, or any detectable action in relation to the document to be signed, i.e. anything that happened to the document. Thereby, even more information of the signing experience and how the user has experienced what he/she was signing is collected and stored together with the signed human readable data. The detection of the action may be stored as a so called evidence log. Probably the action comprises many actions all stored in the evidence log.

[00028] According to an embodiment, the method of fig. 3 further comprises digitally signing 308 the signed human readable data with its appendices, e.g. the evidence log and the recorded MMI state digitally. Consequently, all the

documentation of the signing experience including the actual data signed are stored together and digitally signed, which makes it harder to tamper with the data. [00029] Fig. 4 shows a communication apparatus 130, 135 according to an embodiment, the communication apparatus (which may also be called a client) may comprise a communication unit 420 for communicating to/from the network, e.g. to/from the second communication apparatus 135 and/or to/from the server 120. The communication apparatus 130, 135 may further comprise a man- machine interface, MMI, 414. The MMI may comprise an output unit 414a for providing a user with data and an input unit 414b for making it possible for a user to input data to the communication apparatus. The output unit may be a display or screen. The input unit may be e.g. a key board or a touch screen. The

communication apparatus 130, 135 further comprises a receiving unit 402 for receiving an invitation to sign the human readable data and a presenting unit 404 for presenting the human readable data at the output unit 414a of the MMI of the communication apparatus. The communication apparatus 130, 135 further comprises a detection unit 406 for detecting that a process of signing the human readable data is being performed, a recording unit 408 for recording a state of the MMI comprising the human readable data, in response to detecting that a process of signing the human readable data is being performed and a sending unit 410 for sending the recorded MMI state to the server. The communication apparatus may further comprise a storage unit 412 for storing e.g. the recorded state of the MMI or any other actions.

[00030] According to an embodiment, the first communication apparatus 130 may receive an invitation to sign a human readable data in electronic format, such as a document, electronically. The document may be in any type of format. The invitation may have been sent from the server 120 or from the second

communication apparatus 135. The invitation may be sent in any possible way via any possible communication technology, such as e-mail, a text message e.g. SMS, or by being redirected from one web page to another, or by being redirected from one view in an application to another view in another application, or by being handed as a tablet on which the document is displayed. The invitation may or may not comprise the actual document to be signed. [00031 ] At the first communication apparatus 130, the document is then presented at the output unit 414a of the MMI 414, i.e. the screen. As a user of the communication apparatus goes through the document to be signed, the detection unit 406 may detect actions performed to the document. Such actions may be e.g. when the user inputs data to the document, or just scrolls the document, or any detectable action in relation to the document to be signed, i.e. anything that happened to the document. When an action is detected, the action may be recorded by the recording unit 408. The detected action may be stored in the storage unit 412. The storage unit 412 may be a temporary storage unit. A recording of an action may be to record the result of the action in the man-machine interface. Alternatively, the detection unit may also be arranged with a video or audio recorder, for detecting and recording actions performed by the user at the communication apparatus.

[00032] According to an embodiment, a screen-shot is recorded of a

communication apparatus MMI state when a person is signing the document. The communication apparatus MMI state may be the current MMI output state, i.e. what the screen looks like for the person signing the document. When the detection unit 406 detects that a signing process is performed or to be performed, the screen shot may be recorded. The screen shot may be recorded at the beginning of the signing process, e.g. at a top of the document. Further, the screen shot may be recorded after signing has been executed. The screen shot may also, or alternatively, be recorded during signing of the document.

Alternatively, screen shots may be recorded repeatedly, with a certain time period between each recording. The detection unit 406 may be arranged to detect that the user is about to sign the document, e.g. when data is input by the user in a signing field of the document. One or many screen-shots may be taken of the signing procedure. According to an embodiment, when the signing process displays a confirmation message on the screen confirming that the signatory has signed, a screenshot may be taken of the signing environment of the signatory including the confirmation message and the signed document in the background. According to another embodiment, a screen shot is taken of the signature of the signatory. The signature may for example be clicking on a button on the screen.

[00033] After detecting and recording a number of document actions and screen shots of documents, the sending unit 410 of the first communication apparatus 130 triggers sending of the recorded document actions and screen shots to the server 120 via its communication unit 420. If the signing of the document is performed in an instance of the signing process running on the first communication apparatus, e.g. as an app in a cellular phone, also the signed document may be sent together with the screen shots. In addition, also other information such as location of the device and time of signing may be sent together with the screen shots.

[00034] Fig. 5 shows an embodiment of the server 120. The server may comprise a communication unit 510 for communicating to/from the network, e.g. to/from the first communication apparatus 130 and/or to/from the second communication apparatus 135. The server 120 comprises a sending unit 502 for triggering sending of an invitation to sign the human readable data to the communication apparatus. The invitation is sent via the communication unit 510. The server further comprises a receiving unit 504 for receiving a recorded MMI state of the apparatus, from the apparatus, wherein the MMI state has been recorded in connection with a process of signing the human readable data. Further, the receiving unit 504 may be arranged to receive the recorded document actions. The recorded document actions and MMI states, i.e. screen-shots, may be received via the communication unit 510. The server further comprises an arranging unit 506 for appending the recorded MMI state to the signed human readable data, or in connection with the signed human readable data. The arranging unit 506 may further be arranged for appending the received recorded actions in connection with the electronic document. The arranging unit 506 may also be configured to arrange other electronic document data to the document, such as transaction ID.

[00035] According to an embodiment, the arranging unit 506 is configured to gather and append verification data to the document, as a verification data collection. The verification data may be appended to the signed electronic document. The arranging unit 506 may further be configured to append the evidence documentation to the document. The arranging unit may further be configured to append the evidence log to the document. The evidence log may be all, or at least many of the recorded document actions. The arranging unit may further be configured to append the number of screen-shots of the signing procedure to the document. The number of screen-shots may be appended in an ordered manner, such as in a time order, i.e. in the order of time in which the screen-shots were taken. Other information about the screen shot may be appended such as an explanation of what is performed, a source from which the screen-shots are taken, (e.g. "A view in Internet Explorer"), time, location and other information related to the screen-shots. The arranging unit may further be configured to append the digital signature information of the document, to the document. Further, the server may comprise a signing unit 508 configured to sign the document and all its appended documentation digitally, as a joint package.

[00036] As mentioned, screen shots of the signing experience are captured, stored and appended to the electronically signed document to prove authenticity of the signed document. Also other data may be appended to the signed document, as will be described below.

[00037] A verification page may be appended to the signed document. The verification page is intended to make the most important transaction information as easily available as possible. The verification page may also be called a verification data collection. The key details are which documents were signed, by whom, when and how. The verification page may contain any or all of the following information:

• Transaction ID

• Selected document details

• Selected signing person details

• Selected non-signing person details

• Selected actions of each signing person, time of action and IP-number

• A seal confirming that a third party has verified the transaction

At the end of the verification page there may be brief documentation describing what the verification page is. The documentation is intended to give the reader the information necessary in order to understand the nature of the document, understand where to find any extra documentation about the document and understand how to simply verify the integrity of the document. This information is intended to be understandable and useful independently of any used technique for storing and appending documents.

[00038] An evidence documentation may be appended to the signed document. The evidence documentation is a documentation about all data appended to the signed document, called the evidence package. The evidence documentation is intended as an instruction manual of how to interpret the different parts of the evidence package and is intended to make understanding and use of the evidence package as easily available as possible and independently of any third party.

[00039] An evidence log may be appended to the signed document. As much as possible of the signatory^'s actions on the communication apparatus may be recorded as log data in the evidence log. Note that the verification page may only contain selected transaction log data with the intention to make a preselected set of transaction history available. The difference is that the evidence log contains all, or at least many transaction log data, with the intention to make more or less all transaction history available. In other words, the evidence log may contain all, or at least many, of the recorded document actions. Also, to enhance the redundancy qualities of the evidence log, the log data may be made redundant by recording as much signatory action data as possible, or at least much signatory action data. The evidence log may be written in plain text and/or in HTML or in any other readable format.

[00040] An evidence of intent may be appended to the signed document. The evidence of intent comprises the screen shots of the signing experience, and a description of who signed how. The evidence of intent may also comprise a time point when the screen shot was taken. An example of an evidence of intent, with clickable links to the captured screenshots is shown in Appendix 1 . [00041 ] A digital signature documentation may be appended to the document. The digital signature documentation comprises an algorithm for how to prove the documents integrity mathematically. With the help of the digital signature documentation the signed document integrity can be tested mathematically. Note that the digital signature documentation may not be intended as the main route for proving the document integrity. The digital signature documentation is mainly intended as a last resort when all other methods of verifying the integrity have failed. The digital signature documentation provides evidence that the document has not been tampered with after a certain date.

[00042] A digital signature may be appended to the signed document with its appended evidence package. Once all documentation has been appended to the signed document, a document wrapper may be digitally signed with an industry standard digital signature including a strong time stamp. The document wrapper may comprise the digitally signed document and the data that has been appended to the document.

[00043] According to an embodiment, the invention may be realized by a computer program comprising computer readable code means, which when run in a communication apparatus and a server, respectively, causes the communication apparatus and the server to perform the methods of the invention. Further, the invention may be realized by a computer program product comprising a computer program stored on a computer readable medium. The receiving, presenting, detection, recording and sending units 402-410 of the communication apparatus shown in fig. 4 may be arranged in an arrangement 401 . The arrangement 401 may be implemented e.g. by one or more of: a processor or a micro processor and adequate software and storage therefore, a Programmable Logic Device, PLD, or other electronic component(s)/processing circuit(s) configured to perform the actions, or methods, mentioned above. In the case that the invention is realized by a computer program, the computer program, which is arranged to cause the communication apparatus to perform the method described in connection with fig. 2, may be stored in the storage unit 412, and executed by the processor 401 . The receiving, presenting, detection, recording and sending units 402-410 are then realized as computer program modules for execution by the processor.

[00044] Similarly, the sending, receiving, arranging and possibly also the signing units 502-508 of the server 500 shown in fig. 5 may be arranged in an

arrangement 501 . The arrangement 501 may be implemented e.g. by one or more of: a processor or a micro processor and adequate software and storage therefore, a Programmable Logic Device, PLD, or other electronic component(s)/processing circuit(s) configured to perform the actions, or methods, mentioned above. In the case that the invention is realized by a computer program, the computer program, which is arranged to cause the server to perform the method described in connection with fig. 3, may be stored in the storage unit 512, and executed by the processor 501 . The sending, receiving, arranging and signing units 502-508 are then realized as computer program modules for execution by the processor,

[00045] According to an embodiment, the version Id of the computer program version that was used is appended to the document. Thereby, it may be possible to tie the results back to the correct computer program version, which may be reused to show e.g. communication apparatus MMI states with this program version.

[00046] When all data has been appended to the document, the electronically signed document and all data appended to the document may be sent to signing parties, for example to the first communication apparatus 130, if it belongs to any of the signing parties, by the sending unit 502. Further, the electronically signed document and all its appended data may also be sent to another party to the agreement, e.g. to the second communication apparatus 135 if it belongs to the other party.

[00047] According to an optional embodiment, the communication apparatus (or the identity of the communication apparatus) may be verified. Verification may be performed in any part of the method, for example when receiving the invitation or during the signing process. Verification may be performed via different methods and communication technologies, such as email or text messages, e.g. SMS, Public Key Infrastructure, PKI, signatures, IP-address, etc.

[00048] Although the description above contains a plurality of specificities, these should not be construed as limiting the scope of the concept described herein but as merely providing illustrations of some exemplifying embodiments of the described concept. It will be appreciated that the scope of the presently described concept fully encompasses other embodiments which may become obvious to those skilled in the art, and that the scope of the presently described concept is accordingly not to be limited. Reference to an element in the singular is not intended to mean "one and only one" unless explicitly so stated, but rather "one or more." All structural and functional equivalents to the elements of the above- described embodiments that are known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed hereby. Moreover, it is not necessary for an apparatus or method to address each and every problem sought to be solved by the presently described concept, for it to be encompassed hereby.

Claims

1 . A method performed by a communication apparatus (130, 135) of a data communication system for proving authenticity of electronically signed human readable data, the data communication system comprising the communication apparatus and a server (120), the method comprising:

receiving (202) an invitation to sign the human readable data;

presenting (204) the human readable data at a man-machine interface, MMI, of the communication apparatus;

detecting (206) that a process of signing the human readable data is being performed;

recording (208) a state of the MMI comprising the human readable data, in response to detecting that a process of signing the human readable data is being performed;

sending (210) the recorded MMI state to the server.

2. Method according to claim 1 , wherein the MMI state is recorded (208) by capturing a screen-shot of the MMI state.

3. Method according to claim 1 or 2, wherein the method further comprises detecting an action performed to the document; recording the detected action and sending the detected action to the server.

4. Method according to any of claims 1 -3, wherein the recording (208) of a state of the MMI comprises recording a first screen shot at the beginning of the signing process and a second screen-shot when signing has been executed.

5. Method according to any of the preceding claims, wherein the sending (210) of the recorded MMI state to the server comprises sending the recorded MMI state together with the signed human readable data.

6. A method performed by a server (120) of a data communication system for proving authenticity of electronically signed human readable data, the data communication system comprising the server and a communication apparatus (130, 135), the method comprising:

sending (302) an invitation to sign the human readable data to the communication apparatus;

receiving (304) a recorded MMI state of the apparatus, from the apparatus, wherein the MMI state has been recorded in connection with a process of signing the human readable data;

appending (306) the recorded MMI state to the signed human readable data.

7. Method according to claim 6, further comprising:

receiving a detection of an action performed to the human readable data,

appending the detection of an action to the human readable data.

8. Method according to claim 6 or 7, further comprising:

signing (308) the signed human readable data with the appended recorded MMI state and, possibly, the appended detection of action, digitally.

9. A communication apparatus (130, 135) of a data communication system, operable for proving authenticity of a process of signing human readable data, the data communication system comprising the communication apparatus and a server (1 10), the apparatus comprising:

a receiving unit (402) for receiving an invitation to sign the human readable data;

a presenting unit (404) for presenting the human readable data at a man-machine interface, MMI, of the communication apparatus;

a detection unit (406) for detecting that a process of signing the human readable data is being performed;

a recording unit (408) for recording a state of the MMI comprising the human readable data, in response to detecting that a process of signing the human readable data is being performed

a sending unit (410) for sending the recorded MMI state to the server.

10. Communication apparatus according to claim 9, wherein the recording unit (408) is arranged to record a state of the MMI by capturing a screen-shot of the MMI state in response to detecting that a process of signing the human readable data is being performed.

1 1 . Communication apparatus according to claim 9 or 10, wherein the sending unit (410) is arranged for sending the recorded MMI state to the server together with the signed human readable data.

12. A server (120) of a data communication system operable for proving authenticity of a process of signing human readable data, the data communication system comprising the server and a communication apparatus (130, 135), the server (120) comprising:

a sending unit (502) for sending an invitation to sign the human readable data to the communication apparatus;

a receiving unit (504) for receiving a recorded MMI state of the apparatus, from the apparatus, wherein the MMI state has been recorded in connection with a process of signing the human readable data;

an arranging unit (506) for appending the recorded MMI state to the signed human readable data.

13. Server according to claim 12, further comprising a signing unit (508) for digital signing of the signed human readable data with the appended recorded MMI state.

14. A computer program product, comprising computer readable code means, which when run in a communication apparatus (130, 135) causes the communication apparatus to perform the corresponding method according to any of the claims 1 -5.

15. A computer program product, comprising computer readable code means, which when run in a server (1 10) causes the server to perform the corresponding method according to any of the claims 6-8.