Announcement PDF 05/11/2026 Sentry 7 PLC (the “Company” or “Sentry 7”) (previously named Vault Ventures PLC) Teaming Agreement with PA Consulting The Company is pleased to announce that its engineering partner, Whitespace, has entered into a teaming agreement with PA Consulting (“PA”) to deliver a joint co-design and proof of value (“PoV”) programme for the Company’s secure messaging platform for the regulated financial sector (the “Platform”). As previously announced, the Company, via Whitespace is developing the Platform to address challenges being faced by financial institutions: the exposure of existing messaging systems to future quantum computing attacks, and the difficulty of meeting regulatory requirements for auditable communications. The Platform is intended to offer post-quantum cryptographic protection designed to safeguard communications against “harvest now, decrypt later” attacks; a selective disclosure capability that allows banks to share specific, auditable information with regulators without exposing all sensitive communications; on-device artificial intelligence features, such as message summarisation, designed to keep sensitive data on the user’s device; and secure document sharing with integrity and authenticity controls. Under the agreement, Whitespace will supply its post-quantum cryptographic technology and lead the build of the PoV, which is funded by the Company. PA will lead stakeholder engagement, compliance mapping and programme delivery. Whitespace intends to work with regulated financial institutions as co-design partners, who are expected to provide use cases, operational constraints, a test environment and acceptance criteria. The Company will provide further information on the progress of the programme in due course. The programme is expected to proceed in four stages: a short discovery phase, a design sprint with the co-design partner(s), a funded PoV build, and a pilot with a regulator walkthrough. Success will be assessed against independent post-quantum cryptographic validation and penetration testing, regulatory feedback on the selective disclosure capability, and the outcome of the bank pilot, including the path to production and commercial terms. There can be no certainty that the PoV will achieve its objectives, that a co-design partner will be secured, or that the platform will be commercialised. Any commercial terms will be subject to separate agreement. Mark Evans-Smith, proposed CEO and Executive Director commented: “Our aim is to create a secure messaging platform for the financial sector that is designed to withstand future quantum threats and to support their regulatory obligations. Turning that ambition into a solution that be relied upon requires the support of a trusted company with deep expertise to help deliver it, and PA Consulting is that company. Its experience in stakeholder engagement, compliance mapping and programme delivery will help turn our post-quantum technology into a platform built around real operational needs. We look forward to working with PA Consulting and our co-design partners as previously announced, and to sharing further progress as the programme develops.” For more information please contact: Sentry 7 PLC Brian Stockbridge Investor Hub Alfred Henry Corporate Finance Ltd Nick Michaels, Maya Klein Wassink AQSE Corporate Advisor +44 (0) 20 8064 4056