Picture of the Handsome Devil

Dr. Donal E. O'Mahony

Professor in Computer Science

Postal Address

Computer Science Department
Trinity College
Dublin 2

E-Mail: Donal.OMahony (at) cs.tcd.ie
Tel: +353 1 896 8445
Fax: +353 1 677 2204

Donal O'Mahony is Professor of Computer Science at Trinity College Dublin. His research to date has focussed on the challenges of delivering a future Internet that can provide services to a highly connected society with reliability and security. Over the years, this had led to explorations into cryptography, network protocols, security application, mobility, ad-hoc networking and the software engineering of networked systems. Among his recent hot-topics of interest are the Cloud Computing model, network protocols and architectures to support this. His environmental interests have stimulated an interest in how cloud computing itself can minimize its environmental impact and how it can allow energy use minimization in other areas.

He is a strong advocate of applying the research prowess of leading Universitites in support of the Knowledge Economy. He lectures on Technology Entrepreneurship and Sustainable Computing at Trinty and maintains strong links with Irish high-tech industry through his research activities. In the period 2004-2009, he was founder director of the Centre for Telecommunications Value-Chain Research (CTVR). This centre created an unprecedented colllaboration among teams from 8 seperate Irish third level institutions allowing them to work in an effective 100-man team effort to deliver top-quality research across a range of topics in telecommunications. The initiative acted as the catalyst for the establishment of Bell Labs Ireland -a jewel in the crown for Irish research in ICT. Among the many achievements of CTVR under O'Mahony's leadership were the creation of multiple spin-out companies, the successful commercial licencing of research results and the publication of over 400 high-quality papers in international journals and conferences.

Career to Date

Donal O'Mahony graduated with first class honours in Engineering from Trinity College Dublin in 1982. His first job was with SORD Computer Corporation in Japan and Dublin. Sord was a Japanese startup company with aspirations to displace Apple as the then leader in micro-computers. O'Mahony served as their operating system specialist, working with CP/M, CP/M-86, the UCSD P-System, Sord's proprietary operating system and the emerging MS-DOS. A brief exposure to the new IBM PC in late 1982 caused him to go to work with IBM Ireland helping to launch the original IBM PC. He was recruited by Trinity College as a lecturer in Computer Science in 1984 where he later completed a PhD in the area of software reusability.

Around 1990, he set up the Networks & Telecommunications Research Group which did pioneering work in the esablishment of the global X.500 directory service (initially implemented over an academic X.25 network infrastructure called IXI) and in using the system in a wide variety of applications including a pre-web form of electronic commerce. In 1988, when Local Area Networks were beginning to appear on the mass-market, he published a textbok with Prentice-Hall publishers entitled Local Area Networks and their Applications which became a best-seller in this emerging field and was subsequently published in Japanese, Polish as well as in a low-cost edition for the Indian market. . His research group took part in the Cordless Business Communication (COBUCO) European project in 1996 which aimed to produce a demonstrator for the emerging 3G mobile cellular system. This experience led the group to develop a vision for 4G systems that eschewed traditional cellular architectures for a more interenet-like system that provides seamless mobility, end-to-end security across a network operated by very many competing nework operator. This vision is still being actively pursued today.

The group has also been very active in the development of novel security protocols, in particular in Electronc Payment and in 1997, he and two of his research students published Electronic Payment Systems with Artech House. This book became the leading text in this area, went to 2nd edition, and was awarded a 'best seller in class" award by Amazon.Com in 2000.

In 1998/99, O'Mahony was awarded a Fulbright scholarship to spend a sabbatical year at Stanford, California. In addition to his research work at Stanford he became involved with the very active technology entrepreneurship programme. He started a web company called LetterPost.Com in late 1998. A business plan was developed in conjunction with a colleague and entered into Stanford Entrepreneur's E-Challenge where it was repeatedly subjected to the scrutiny of judges from the Sand Hill road venture capital community and reached the final of the competition [24Mb Newsclip from Channel 4 News, NY Times Article]. O'Mahony continued as CEO of letterpost.com until it was acquired by the Escher Group in 2000.

O'Mahony is a senior member of the IEEE and was made a fellow of Trinity College in May 2000.

According to this infographic, he is 7th in a list of people who might have created Bitcoin.


Donal O'Mahony is author of two books, the first Local Area Networks & their Applications was published by Prentice-Hall in 1988, this has been translated into Japanese and published by Kaibundo Publishing corporation.
A second book entitled "Electronic Payment Systems" was published by Artech House in May 1997.

A list of publications correct to August 2013 is given here . Older lists that I don't want to lose the link to are here, with a more complete list available here.


Over the course of his teaching career at Trinity College, he has been responsible for the following courses:

He also designed the content for the communications stream of a new four year undergraduate degree programme in Information and Communications Technology launched in October 1997.

In October 2000, he was appointed as course director for the B.A.(Mod) in Computer Science and was responsible for its successful accreditation by Ireland's Professional Engineering Body.


From 1996-1999 he delivered regular seminars to European audiences on Electronic Payment Systems

In the early days of Voice-over-IP (around 1997/1998), he also ran courses on the emerging Internet Telephony area. The slides are (available here) give an interesting snapshot of the VoIP situation in 1998 and may one day be of historical interest.

These were organized by Technology Appraisals of London, England.

Patent Activity

O'Mahony has acted as expert witness in patent litigation involving his expertise in both electronic payment and in cellular and internet networking.

for Cooley Godward LLP where the client was a major internet auction house

for Kirkland & Ellis LLP where the client was a major internet bookseller


Leisure Pursuits

When he gets a chance, he enjoys sailing. Mainly for his own use, he has compiled a Sailing in Ireland page containing some useful links. He is also a bit interested in Trees of Trinity.

Last Updated: February 2010
Donal.OMahony (at) cs.tcd.ie